JP2012231125A - Organic electroluminescent element, and light emitting device, display device and lighting system including the organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element capable of simultaneously satisfying high external quantum efficiency and high power efficiency, in an organic electroluminescent element in which a light emitting material is aligned in a direction horizontal to a substrate.SOLUTION: There are provided: an organic electroluminescent element 10; and a light emitting device, a display device and a lighting system which include the organic electroluminescent element. The organic electroluminescent element 10 includes a positive electrode 3, a first intermediate organic layer 4, 5 comprising at least one organic layer, a light emitting layer 6, a second intermediate organic layer 7, 8 comprising at least one organic layer, and a negative electrode 9, in the order on a substrate 2. In the organic electroluminescent element 10, light is extracted from a side of the positive electrode 3, the light emitting layer 6 contains a light emitting material aligned in a direction horizontal to the substrate 2, the order parameter of the light emitting material in the light emitting layer 6 is equal to or greater than 0.7, and the film thickness T1 (nm) of the first intermediate organic layer 4, 5 and the film thickness T2 (nm) of the second intermediate organic layer 7, 8 satisfy relationships: 1.1<T1/T2<4.0 and 20 nm<T2<80 nm.

Description

  The present invention relates to an organic electroluminescent element, and a light emitting device, a display device, and a lighting device using the organic electroluminescent element.

An organic electroluminescent element is a self-luminous display device, and is used for displays and illumination. A display using an organic electroluminescent element has advantages in display performance such as high visibility and less viewing angle dependency compared to conventional CRTs and LCDs. There is also an advantage that the display can be reduced in weight and thickness.
In addition to the advantages of lighter weight and thinner layers, organic electroluminescent elements have the potential to realize illumination in a shape that could not be realized before by using a flexible substrate.

As described above, the organic electroluminescent device has excellent characteristics including the above-mentioned matters, but generally, the refractive index of each layer constituting the organic electroluminescent device including the light emitting layer is higher than that of air. For example, in an organic electroluminescent element, the refractive index of an organic layer such as a light emitting layer is 1.6 to 2.1. For this reason, the emitted light is easily totally reflected at the interface, and its light extraction efficiency is less than 20%, and most of the light is lost.
For example, a generally known organic electroluminescent element is configured to include an organic layer disposed between a pair of electrode layers on a substrate. The organic layer includes a light emitting layer, and the organic electroluminescent element emits light emitted from the light emitting layer from the light extraction surface side. In this case, there is a problem that the light extraction efficiency is low because the total reflection component that is light having a critical angle or more cannot be extracted at the light extraction surface or the interface between the electrode layer and the organic layer.

  In order to solve such a problem, for example, a method for improving the light extraction efficiency by using a light emitting material oriented in the horizontal direction in the light emitting layer has been proposed (Non-Patent Document 1).

  However, in this proposal, the layer configuration other than the light emitting layer is not studied, and further improvement of the external quantum efficiency is demanded.

Organic Electronics, Vol. 12, no. 5,809-817 (2011)

  In view of the conventional problems as described above, it is an object of the present invention to achieve the following objects. That is, the present invention provides a high external quantum efficiency and high power efficiency in an organic electroluminescent device in which the order parameter in the light emitting layer of the light emitting material is 0.7 or more and the light emitting material is oriented in the horizontal direction with respect to the substrate. It is an object of the present invention to provide an organic electroluminescent element that can satisfy both of the above, and a light emitting device, a display device, and a lighting device using the organic electroluminescent element.

  Means for solving the above-mentioned problems are as follows.

[1]
A substrate has an anode, a first intermediate organic layer composed of at least one organic layer, a light emitting layer, a second intermediate organic layer composed of at least one organic layer, and a cathode in this order. An organic electroluminescent device to be taken out,
The light emitting layer contains a light emitting material oriented in the horizontal direction with respect to the substrate, and the order parameter of the light emitting material in the light emitting layer is 0.7 or more,
The relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.1 <T1 / T2 <4.0 and 20 nm. <T2 <80 nm, an organic electroluminescent element.
[2]
The organic electroluminescent element according to the above [1], wherein the luminescent material is a platinum complex, a pyrene derivative, or a π-conjugated compound represented by the following general formula (R-1).

(Here, Ar _{1 to} Ar ₃ each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and Ar _{4 to} Ar ₇ each independently represents an aromatic carbon atom having 6 to 30 carbon atoms. Represents a hydrogen group, and two aromatic hydrocarbon groups constituting Ar ₄ and Ar ₅ are bonded directly or via a substituent to form a condensed heterocyclic ring with N substituted by Ar ₄ and Ar _5. Alternatively, two aromatic hydrocarbon groups constituting Ar ₆ and Ar ₇ may be bonded directly or through a substituent to form a condensed heterocyclic ring with N substituted by Ar ₆ and Ar _7. L ₁ and L ₂ each independently represents a vinylene group or an acetylene group, and l, m, n, o and p each independently represent an integer of 0 to 6, but any one of l, n and p One is not 0.)
[3]
The organic electroluminescent element according to the above [1] or [2], wherein the light emitting layer further contains a host material, and the host material is a triphenylene derivative.
[4]
The maximum light emission wavelength of the light emitting material is 600 to 700 nm, and the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1 The organic electroluminescent element according to any one of [1] to [3], wherein .2 <T1 / T2 <4.0 and 30 nm <T2 <80 nm.
[5]
The maximum emission wavelength of the light emitting material is 400 to 500 nm, and the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1 .1 <T1 / T2 <3.0, and 20 nm <T2 <70 nm, The organic electroluminescence device according to any one of the above [1] to [3].
[6]
The organic electroluminescent element according to any one of [1] to [5] above, wherein a light extraction layer is formed on the substrate.
[7]
The organic electroluminescent element according to the above [6], wherein the refractive index of the substrate is 1.8 or more.
[8]
The light-emitting device using the organic electroluminescent element of any one of said [1]-[7].
[9]
The display apparatus using the organic electroluminescent element of any one of said [1]-[7].
[10]
The illuminating device using the organic electroluminescent element of any one of said [1]-[7].

  According to the present invention, in an organic electroluminescent device in which the order parameter in the light emitting layer of the light emitting material is 0.7 or more and the light emitting material is oriented in the horizontal direction with respect to the substrate, high external quantum efficiency and high power efficiency. It is possible to provide an organic electroluminescent element that can satisfy both of the above and a light emitting device, a display device, and a lighting device using the organic electroluminescent element.

It is the schematic which shows an example of a structure of the organic electroluminescent element which concerns on this invention. It is the schematic which shows an example of the light-emitting device which concerns on this invention. It is the schematic which shows an example of the illuminating device which concerns on this invention. It is a schematic diagram for demonstrating the molecular length of material.

  Hereinafter, the present invention will be described in detail. In the present specification, “to” indicates a range including the numerical values described before and after the minimum and maximum values, respectively.

In the present invention, the substituent group A and the substituent group B are defined as follows.
(Substituent group A)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, for example vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), amino group (preferably 0 to 30 carbon atoms, more preferably 0 carbon atoms) -20, particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino, etc.), an alkoxy group (preferably having 1 to 30 carbon atoms). More preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), an aryloxy group (preferably 6 to 6 carbon atoms). 30, more preferably 6-20 carbon atoms, particularly preferably 6-12 carbon atoms, Enyloxy, 1-naphthyloxy, 2-naphthyloxy, etc.), a heterocyclic oxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms). For example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), an acyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, for example, acetyl , Benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonyl, ethoxy Carbonyl etc.), an aryloxycarbonyl group (preferably Has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonyl. ), An acyloxy group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetoxy and benzoyloxy), an acylamino group (preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, particularly preferably 2-10 carbon atoms, and examples thereof include acetylamino, benzoylamino, and the like, and an alkoxycarbonylamino group (preferably having 2-2 carbon atoms). 30, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, etc.), aryloxycarbonylamino group (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl And sulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino and benzenesulfonylamino). ), A sulfamoyl group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenyl Sulfamoyl, etc.), a carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, Phenylcarbamoyl etc.), alkylthio group ( Preferably, it has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylthio, ethylthio and the like, and an arylthio group (preferably 6 to 30 carbon atoms). , More preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic thio group (preferably 1 to 30 carbon atoms, more preferably 1 to carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like, and a sulfonyl group (preferably having 1 carbon atom). To 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl). Sulfinyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfinyl and benzenesulfinyl. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid. An amide group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenylphosphoric acid amide), a hydroxy group , Mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group ( An aromatic heterocyclic group is also included, preferably 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, Is, for example, a nitrogen atom, oxygen atom, sulfur atom, phosphorus atom, silicon atom, selenium atom, tellurium atom, specifically pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, And isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl group, azepinyl group, silolyl group and the like. A silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). Ryloxy group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyloxy and triphenylsilyloxy), phosphoryl group (for example, A diphenylphosphoryl group, a dimethylphosphoryl group, etc.). These substituents may be further substituted, and examples of the further substituent include a group selected from the substituent group A described above.

(Substituent group B)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, for example vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, including phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), cyano group, heterocyclic group (including aromatic heterocyclic group, Has 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a silicon atom, a selenium atom, and a tellurium atom. Is pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolid Le, benzoimida Lil, benzothiazolyl, carbazolyl, azepinyl group,. Etc. Shiroriru group) can be mentioned. These substituents may be further substituted, and examples of the further substituent include a group selected from the substituent group A.

[Organic electroluminescence device]
The organic electroluminescent element of the present invention comprises an anode, a first intermediate organic layer comprising at least one organic layer, a light emitting layer, a second intermediate organic layer comprising at least one organic layer, and a cathode in this order on a substrate. An organic electroluminescent device for extracting light from the anode side, wherein the light emitting layer contains a light emitting material oriented in a horizontal direction with respect to a substrate, and the order parameter of the light emitting material in the light emitting layer Is 0.7 or more, and the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.1 <T1 / T2 <4.0 and T2 <80 nm.

  The organic electroluminescence device of the present invention is the organic electroluminescence device in which the order parameter in the light emitting layer of the light emitting material is 0.7 or more and the light emitting material is oriented in the horizontal direction with respect to the substrate. The relationship between the film thickness T1 (nm) of the intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer described above is 1.1 <T1 / T2 <4.0 and 20 nm <T2 < By setting the thickness to 80 nm, both high external quantum efficiency and high power efficiency can be satisfied at the same time.

A non-oriented light emitting material that is not oriented in the horizontal direction with respect to the substrate in the light emitting layer, such as an iridium complex that is widely used as a light emitting material in conventional organic electroluminescent elements, has a ratio of light emission of a component that is quenched by a metal. This is not desirable in terms of external quantum efficiency, power efficiency, durability, etc., because the light extraction efficiency to the outside is large and driving at a high voltage is required to increase the light emission luminance. For this reason, in the conventional element using such a non-oriented light emitting material, the film thickness of the organic layer between the light emitting layer and the cathode (that is, the second intermediate organic layer described above is reduced) so that the quenching by the metal can be reduced. The film thickness of the organic layer between the light emitting layer and the cathode is equal to the film thickness of the organic layer between the light emitting layer and the anode (that is, the first film thickness described above). Since it was necessary to be the same as or larger than (corresponding to the film thickness T1 (nm) of the intermediate organic layer) (that is, T1 ≦ T2), there was a problem of deviation from the optimum distance due to optical interference. Furthermore, since the electron mobility of the electron transport layer and the electron injection layer is small and the carrier concentration is low, the driving voltage increases as the thickness of the electron transport layer and the electron injection layer increases, resulting in poor power efficiency. was there.
According to the study by the present inventors, when a light emitting material that is oriented in the horizontal direction with the substrate in the light emitting layer and the order parameter is 0.7 or more is used, the light emission of the component that is quenched by the metal compared to the non-oriented light emitting material. It has been found that the ratio of is greatly reduced. In the organic electroluminescent element using the light emitting material horizontally aligned with respect to the substrate in this way, the thickness of the organic layer between the light emitting layer and the anode (that is, the thickness T1 of the first intermediate organic layer described above). (Corresponding to the film thickness T2 (nm) of the second intermediate organic layer described above) and the thickness of the organic layer between the light emitting layer and the cathode (that corresponds to the film thickness T2 (nm) of the second intermediate organic layer) so as to satisfy the above relationship As a result, the optical interference can be optimized and the thickness of the second intermediate organic layer such as the electron injection layer and the electron transport layer can be reduced, so that both high external quantum efficiency and high power efficiency can be satisfied simultaneously. It has been found that an organic electroluminescent device that can be provided is provided.
The reason for this is not clear, but by using a light-emitting material that is aligned horizontally with respect to the substrate, the ratio of light emission from components that are quenched by metal can be greatly reduced, and the distance between the light-emitting layer and the cathode can be reduced. In addition, when the film thickness of the organic layer between the light emitting layer and the anode and the film thickness of the organic layer between the light emitting layer and the cathode satisfy the above relationship, it is presumed that the amplification effect due to optical interference is optimal.

[Organic electroluminescence device]
Hereinafter, the organic electroluminescent element of the present invention will be described.
The present invention comprises, on a substrate, an anode, a first intermediate organic layer composed of at least one organic layer, a light emitting layer, a second intermediate organic layer composed of at least one organic layer, and a cathode in this order. Provided is an organic electroluminescent device for extracting light from the side.
FIG. 1 shows an example of the configuration of an organic electroluminescent device according to the present invention. In the organic electroluminescent device 10 according to the present invention shown in FIG. 1, a light emitting layer 6 is sandwiched between an anode 3 and a cathode 9 on a support substrate 2, and the anode 3 is formed on the support substrate 2. A light extraction layer 15 is formed on the opposite side of the side. Specifically, a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, a first electron transport layer 7, and a second electron transport layer 8 are laminated in this order between the anode 3 and the cathode 9. Has been.
In the configuration of the organic electroluminescence device shown in FIG. 1, the first intermediate organic layer includes a hole injection layer 4 and a hole transport layer 5, and the film thickness T <b> 1 of the first intermediate organic layer is the hole injection layer 4. And the total thickness of the hole transport layer 5. Similarly, the second intermediate organic layer is composed of the first electron transport layer 7 and the second electron transport layer 8, and the film thickness T2 of the second intermediate organic layer is the film thickness of the first electron transport layer 7 and This is the total film thickness of the second electron transport layer 8.
In view of the properties of the light emitting element, the anode is preferably transparent or translucent.

<Layer structure of organic electroluminescent element>
The configuration of the organic layer of the organic electroluminescent element is not particularly limited as long as the above conditions are satisfied, and can be appropriately selected according to the use and purpose of the organic electroluminescent element. The organic layer is formed on the front surface or one surface of the anode or the cathode.

Specific examples of the layer configuration include the following, but the present invention is not limited to these configurations. In the following layer configuration, the layer described between the anode and the light emitting layer corresponds to the first intermediate organic layer if they are organic layers, and the layer described between the light emitting layer and the cathode is Corresponds to the second intermediate organic layer.
Anode / hole transport layer / light emitting layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / first electron transport layer / second electron transport layer / cathode,
・ Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode ・ Anode / hole injection layer / hole transport layer / block layer / light emitting layer / block layer / Electron transport layer / electron injection layer / cathode.

<Board>
The substrate used in the present invention is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.
In the present invention, when a light extraction layer to be described later is formed on the substrate, using a high refractive index glass as the substrate further reduces the guided light inside the substrate and improves the external quantum efficiency and power efficiency. Preferably, the high refractive index glass has a refractive index of 1.8 or more. The refractive index of the high refractive index glass is usually 2.0 or less.
The anode may be formed so as to be in direct contact with a substrate such as high refractive index glass, or may be formed via a light extraction layer described later.

<Light extraction layer>
In the present invention, it is preferable that a light extraction layer is formed on the substrate because the light extraction layer reduces guided light inside the substrate and improves external quantum efficiency and power efficiency. The light extraction layer formed on the substrate may be formed on the substrate surface opposite to the side where the anode is formed, or on the same substrate surface as the side where the anode is formed, It may be formed at the interface between the substrate and the anode.
Examples of the light extraction layer include a light scattering layer and a prism sheet. Specifically, the light scattering layer is made of an inorganic material such as titanium dioxide or silica, or an organic material such as polystyrene or PMMA. It is a polymer layer in which fine particles are dispersed, and the prism sheet has a triangular pyramid made of an organic material formed by a printing method such as screen printing, embossing, photopatterning, or nanoimprinting.
These layers can be formed by a method of directly forming on the substrate, a method of forming on a film and transferring it to the substrate, a method of adhering the film to the substrate, or the like. These layers may be formed either at the substrate / air interface, or at the substrate / transparent electrode (anode) interface, or both.
Further, either one or both of the light scattering layer and the prism sheet may be used in combination.
The thickness of the light extraction layer is preferably 0.01 μm to 10 μm, more preferably 0.1 μm to 5 μm, and still more preferably 0.5 μm to 3 μm.

<Anode>
The anode usually has a function as an electrode for supplying holes to the organic layer, and the shape, structure, size, etc. are particularly limited as long as the light generated in the light emitting layer of the element can be extracted from the anode side. However, it can be appropriately selected from known electrode materials according to the use and purpose of the light-emitting element. As described above, the anode is usually provided as a transparent or translucent anode.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light-emitting element. The electrode material can be selected as appropriate.

  Regarding the substrate, anode, and cathode, the matters described in paragraphs [0070] to [0089] of JP-A-2008-270736 can be applied to the present invention.

<Organic layer>
The organic layer in the present invention will be described.

-Formation of organic layer-
In the organic electroluminescent device of the present invention, each organic layer is formed by a solution coating process such as a dry film forming method such as an evaporation method or a sputtering method, a transfer method, a printing method, a spin coating method, a bar coating method, an ink jet method, or a spray method. Also, it can be suitably formed. By using the liquid coating process, it is considered that productivity can be improved and the area of the organic EL element can be increased.

  Vapor deposition, sputtering, etc. can be used as dry methods, and dipping, spin coating, dip coating, casting, die coating, roll coating, bar coating, gravure coating, and spray coating as wet methods. An ink jet method or the like can be used. These film forming methods can be appropriately selected according to the material of the organic layer. When the film is formed by a wet method, it may be dried after the film is formed. Drying is performed by selecting conditions such as temperature and pressure so that the coating layer is not damaged.

  The coating solution used in the wet film-forming method (coating process) usually comprises an organic layer material and a solvent for dissolving or dispersing it. A solvent is not specifically limited, What is necessary is just to select according to the material used for an organic layer.

  When the organic electroluminescent element material is used as a coating solution, the content in the coating solution is preferably 0.1 to 50% by mass, more preferably 0.3 to 40% by mass, based on the total solid content. Preferably it is 0.3-30 mass%. The viscosity is generally 1 to 30 mPa · s, more preferably 1.5 to 20 mPa · s, and still more preferably 1.5 to 15 mPa · s.

  The coating solution is preferably used by dissolving the organic electroluminescent element material in a predetermined organic solvent, filtering the solution, and applying the solution on a predetermined support or layer. The pore size of the filter used for filter filtration is preferably 2.0 μm or less, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less made of polytetrafluoroethylene (PTFE), polyethylene, or nylon.

  Examples of the solvent include known organic solvents such as aromatic hydrocarbon solvents, alcohol solvents, ketone solvents, aliphatic hydrocarbon solvents, amide solvents, and the like.

  Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, cumeneethylbenzene, methylpropylbenzene, methylisopropylbenzene, and the like, and toluene, xylene, cumene, and trimethylbenzene are more preferable. preferable. The relative dielectric constant of the aromatic hydrocarbon solvent is usually 3 or less.

  Examples of the alcohol solvent include methanol, ethanol, butanol, benzyl alcohol, cyclohexanol, and the like, butanol, benzyl alcohol, and cyclohexanol are more preferable. The relative dielectric constant of the alcohol solvent is usually 10-40.

  Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methyl Examples include isobutyl ketone, acetyl acetone, acetonyl acetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and the like, and methyl ethyl ketone, methyl isobutyl ketone, and propylene carbonate are preferable. The relative permittivity of the ketone solvent is usually 10 to 90.

  Examples of the aliphatic hydrocarbon solvent include pentane, hexane, octane, decane and the like, and octane and decane are preferable. The relative dielectric constant of the aliphatic hydrocarbon solvent is usually 1.5 to 2.0.

  Examples of amide solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethyl hole muamide, 1,3-dimethyl-2-imidazolidinone, and the like. N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferable. The relative dielectric constant of the amide solvent is usually 30-40.

  The said solvent may be used independently and may use 2 or more types together.

In addition, an aromatic hydrocarbon solvent (hereinafter also referred to as “first solvent”) and a second solvent having a relative dielectric constant higher than that of the first solvent may be mixed and used.
As the second solvent, an alcohol solvent, an amide solvent, or a ketone solvent is preferably used, and an alcohol solvent is more preferably used.
The mixing ratio (mass) of the first solvent and the second solvent is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20/80 to 70/30. A mixed solvent containing 60% by mass or more of the first solvent is preferable.

When the organic layer-forming coating solution contains a compound having a polymerizable group and forms a polymer that forms an organic layer by a polymerization reaction of the compound having a polymerizable group, By light irradiation, the polymerization reaction proceeds and a polymer can be formed.
The heating temperature and time after coating are not particularly limited as long as the polymerization reaction proceeds, but the heating temperature is generally 100 ° C to 200 ° C, and more preferably 120 ° C to 160 ° C. The heating time is generally 1 minute to 120 minutes, preferably 1 minute to 60 minutes, and more preferably 1 minute to 30 minutes.

  Moreover, the polymerization reaction by UV irradiation, the polymerization reaction by a platinum catalyst, the polymerization reaction by iron catalysts, such as iron chloride, etc. are mentioned. These polymerization methods may be used in combination with a polymerization method by heating.

(Light emitting layer)
<Light emitting material>
The light emitting material contained in the light emitting layer in the present invention is oriented in the horizontal direction with respect to the substrate in the light emitting layer. In the present application, “the light emitting material is oriented in the horizontal direction with respect to the substrate” means that the major axis direction of the light emitting material and the horizontal plane direction of the substrate are substantially coincident or in the case of a planar light emitting material. Means a state in which the plane of the luminescent material and the direction of the horizontal plane of the substrate substantially coincide. Whether the luminescent material is oriented in the horizontal direction with respect to the substrate is, for example, ATR-IR deflection measurement, photoluminescence deflection measurement described in non-patent literature (Applied Physics Letters, Vol. 96, 073302), etc. It can confirm by the method of.
The order parameter of the light emitting material in the light emitting layer of the present invention is 0.7 or more. The order parameter of the luminescent material in the luminescent layer is, for example, that a cleaned quartz substrate is placed in a vapor deposition apparatus, a film containing the luminescent material is deposited, a film is formed, the above-mentioned ATR-IR deflection measurement, photoluminescence The order parameter of the luminescent material can be calculated by a method such as measurement of the angle of deflection. The state in which the order parameter measured by such a method is 0.7 or more means that the long axis direction of the light emitting material and the horizontal plane direction of the substrate substantially coincide with each other in the light emitting layer, or planar light emission. In the case of a material, it means a state in which the plane of the luminescent material and the horizontal plane of the substrate are substantially coincident (that is, a state where the luminescent material is oriented in the horizontal direction with respect to the substrate). When the organic electroluminescence is made to emit light, the ratio of light emission of the component that is quenched by the metal is greatly reduced.
The order parameter of the light emitting material in the light emitting layer of the present invention is preferably 0.7 or more and 1.0 or less, more preferably 0.8 or more and 1.0 or less.

As the light-emitting material of the present invention, conventionally known light-emitting materials can be used as long as the light-emitting layer is oriented horizontally with the substrate and the order parameter is 0.7 or more, but the orientation of the light-emitting material is improved. From the viewpoint, the aspect ratio (molecular length / molecular thickness) is preferably larger than 3, more preferably larger than 5, more preferably larger than 5 and further preferably 30 or smaller, particularly preferably 5.3 to 20.
When the aspect ratio is larger than 3, the molecular fluctuation is small and the orientation is prevented from being lowered.

In the present invention, the “molecular length” of the light emitting material and the host material described later is the length of two sides a in the closest rectangle when the molecules of the material are assumed to have a flat plate structure, as shown in FIG. , B means the average value [(a + b) / 2]. Here, the “closest quadrangle” is defined as a quadrangle in which the average value [a + b) / 2] of a and b is the smallest among the quadrilaterals (rectangles or squares) whose two sides are in contact with the molecule. This “molecular length” is defined as follows by theoretical calculation. That is, the density functional method is used. Specifically, using Gaussian 03 (Gaussian, USA), the basis optimization function is 6-31G ^* and the exchange correlation functional is B3LYP / LANL2DZ. Do. Using the optimized structure obtained by the structure optimization calculation, the average length of two sides in the closest rectangle in the ball and stick display is defined as the molecular length.
“Molecular thickness” means that the flat plate portion of the flat plate structure is the x axis and the y axis (for example, the direction of the side of the length a in FIG. 4 is the y axis and the direction of the side of the length b is the x axis). It means the thickness of the molecule in the z-axis direction orthogonal to the x-axis and y-axis when assumed. The molecular thickness is also determined by the same method as the molecular length, and the length in the thickness direction of the molecule in ball and stick display is defined as the molecular thickness.

  As the light emitting material, a phosphorescent light emitting material and a fluorescent light emitting material satisfying the above conditions can be used, and a platinum complex (phosphorescent) having a planar structure in that the aspect ratio tends to be 3 or more. A light emitting material), a pyrene derivative (fluorescent light emitting material), a perylene derivative (fluorescent light emitting material) or a π-conjugated compound (fluorescent light emitting material) represented by the general formula (R-1) described later, and a platinum complex ( From the viewpoint of planarity, it is more preferably a phosphorescent material), a pyrene derivative (fluorescent material) or a π-conjugated compound (fluorescent material) represented by the general formula (R-1) described later.

[Platinum complex]
As a platinum complex, platinum (platinum complex) which becomes a tetradentate which is a planar coordination structure is preferable, and a platinum complex having a salen or porphyrin skeleton is more preferable.

  The platinum complex is preferably a platinum complex represented by the general formula (C-1).

In the formula, Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. L ¹ , L ² and L ³ each independently represents a single bond or a divalent linking group.

General formula (C-1) is demonstrated.
Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. At this time, the bond between Q ¹ , Q ² , Q ³ and Q ⁴ and Pt may be any of a covalent bond, an ionic bond, a coordinate bond, and the like.
As an atom couple | bonded with Pt in Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ >, a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom are preferable, and in Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ > Of the atoms bonded to Pt, at least one is preferably a carbon atom, more preferably two are carbon atoms, particularly preferably two are carbon atoms and two are nitrogen atoms.

Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt by a carbon atom may be an anionic ligand or a neutral ligand, and the anionic ligand is a vinyl ligand, Aromatic hydrocarbon ring ligand (eg benzene ligand, naphthalene ligand, anthracene ligand, phenanthrene ligand), heterocyclic ligand (eg furan ligand, thiophene ligand, pyridine) Ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, thiazole ligand, oxazole ligand, pyrrole ligand, imidazole ligand, pyrazole ligand, triazole A ligand, an oxadiazole ligand, a thiadiazole ligand, and a condensed ring containing them (for example, a quinoline ligand, a benzothiazole ligand, etc.). A carbene ligand is mentioned as a neutral ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a nitrogen atom may be neutral ligands or anionic ligands, and as neutral ligands, nitrogen-containing aromatic hetero Ring ligand (pyridine ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, imidazole ligand, pyrazole ligand, triazole ligand, oxazole ligand, Examples include thiazole ligands and condensed rings containing them (for example, quinoline ligands, benzimidazole ligands), amine ligands, nitrile ligands, and imine ligands. Examples of anionic ligands include amino ligands, imino ligands, nitrogen-containing aromatic heterocyclic ligands (pyrrole ligands, imidazole ligands, triazole ligands and condensed rings containing them) (For example, indole ligand, benzimidazole ligand, etc.)).
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with an oxygen atom may be neutral ligands or anionic ligands, and neutral ligands are ether ligands, Examples include ketone ligands, ester ligands, amide ligands, oxygen-containing heterocyclic ligands (furan ligands, oxazole ligands and condensed rings containing them (benzoxazole ligands, etc.)). It is done. Examples of the anionic ligand include an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, and the like.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a sulfur atom may be neutral ligands or anionic ligands, and neutral ligands include thioether ligands, Examples include thioketone ligands, thioester ligands, thioamide ligands, sulfur-containing heterocyclic ligands (thiophene ligands, thiazole ligands and condensed rings containing them (such as benzothiazole ligands)). It is done. Examples of the anionic ligand include an alkyl mercapto ligand, an aryl mercapto ligand, and a heteroaryl mercapto ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a phosphorus atom may be neutral ligands or anionic ligands, and neutral ligands include phosphine ligands, Examples include phosphate ester ligands, phosphite ester ligands, and phosphorus-containing heterocyclic ligands (phosphinin ligands, etc.). Anionic ligands include phosphino ligands and phosphinyl ligands. And phosphoryl ligands.
The ligands represented by Q ¹ , Q ² , Q ^3, and Q ⁴ may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other. When the substituents of Q ³ and Q ⁴ are linked to each other, the platinum complex represented by the general formula (C-1) becomes a Pt complex of a cyclic tetradentate ligand.

The ligand represented by Q ¹ , Q ² , Q ³ and Q ⁴ is preferably an aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, or an aromatic heterocyclic ring bonded to Pt with a carbon atom. A ligand, a nitrogen-containing aromatic heterocyclic ligand bonded to Pt with a nitrogen atom, an acyloxy ligand, an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, a silyloxy ligand, More preferably, an aromatic hydrocarbon ring ligand bonded to Pt by a carbon atom, an aromatic heterocyclic ligand bonded to Pt by a carbon atom, a nitrogen-containing aromatic heterocyclic coordination bonded to Pt by a nitrogen atom An aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, an aromatic heterocyclic ligand bonded to Pt with a carbon atom, nitrogen Containing atoms bonded to Pt Containing aromatic heterocyclic ligand, an acyloxy ligand.

L ¹ , L ² and L ³ represent a group consisting of a single bond, a double bond, a divalent linking group, or a combination thereof. Examples of the divalent linking group represented by L ¹ , L ² and L ³ include alkylene groups (methylene, ethylene, propylene, etc.), arylene groups (phenylene, naphthalenediyl), heteroarylene groups (pyridinediyl, thiophenediyl, etc.) ), Imino group (—NR—) (such as phenylimino group), oxy group (—O—), thio group (—S—), phosphinidene group (—PR—) (such as phenylphosphinidene group), silylene group (-SiRR'-) (dimethylsilylene group, diphenylsilylene group, etc.), a carbonyl group, or a combination thereof. These linking groups may further have a substituent. R and R ′ each independently represents a substituent. As these substituents, those mentioned as the substituent group A can be applied. When there are a plurality of the substituents, the substituents may be connected to each other to form a ring.
From the viewpoint of the stability of the complex and the emission quantum yield, L ² and L ³ are preferably a single bond, an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group, or a silylene group, and more preferably. Is a single bond, an alkylene group, an arylene group or an imino group, more preferably a single bond, an alkylene group or an arylene group, still more preferably a single bond, a methylene group or a phenylene group, still more preferably a single bond. A methylene group in which two hydrogen atoms are substituted, particularly preferably a single bond, a dimethylmethylene group, and most preferably a single bond.

L ¹ is preferably an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group, a silylene group or a carbonyl group, more preferably an alkylene group, an arylene group or an imino group, still more preferably an alkylene group Group and imino group, particularly preferably methylene group and imino group. These may have a substituent, and as the substituent, those exemplified as the substituent group A can be applied. When there are a plurality of the substituents, the substituents may be connected to each other to form a ring.
L ¹ is more preferably a single bond, a methylene group in which two hydrogen atoms are substituted, or an arylimino group which may be substituted, and more preferably a dimethylmethylene group, an ethylmethylmethylene group, a methylpropylmethylene group, isobutylmethyl. A methylene group, a cyclohexanediyl group, a cyclopentanediyl group, a fluoromethylmethylene group and a phenylimino group, particularly preferably a dimethylmethylene group and a phenylimino group. If possible, these groups may be further substituted with the groups mentioned in the substituent group A.

  Among the platinum complexes represented by the general formula (C-1), a preferable embodiment includes a platinum complex represented by the following general formula (C-2).

In the formula, L ²¹ represents a single bond or a divalent linking group. A ²¹ , A ²² , B ²¹ , and B ²² each independently represent a carbon atom or a nitrogen atom. However, two or more of A ²¹ , A ²² , B ²¹ , and B ²² represent a nitrogen atom. Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ each independently represent a benzene ring or a nitrogen-containing aromatic heterocycle.

General formula (C-2) is demonstrated.
L ²¹ represents a single bond or a divalent linking group, and the preferred range is the same as L ¹ in the general formula (C-1).

A ²¹ , A ²² , B ²¹ and B ²² each independently represent a carbon atom or a nitrogen atom, and two or more of them represent a nitrogen atom. Furthermore, it is preferable that two or three of A ²¹ , A ²² , B ²¹ and B ²² represent a nitrogen atom, more preferably two represent a nitrogen atom. From the viewpoint of the stability of the complex, it is preferable that A ²¹ and A ²² represent a nitrogen atom, or that B ²¹ and B ²² represent a nitrogen atom.

Z ²¹ , Z ²² , Z ²³ and Z ²⁴ each independently represent a benzene ring or a nitrogen-containing aromatic heterocycle.
Examples of the nitrogen-containing aromatic heterocycle represented by Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ include a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, an imidazole ring, a pyrazole ring, an oxazole ring, and a thiazole ring. , Triazole ring, oxadiazole ring, thiadiazole ring and the like.
From the viewpoint of orientation and stability as a material for an organic electroluminescence device, the ring represented by Z ²¹ and Z ²² is preferably a benzene ring, a pyridine ring, a pyrazine ring, an imidazole ring, or a pyrazole ring, and more preferably. Are a benzene ring, a pyridine ring, and a pyrazole ring.
From the viewpoint of the stability of the complex, emission wavelength control and emission quantum yield, the ring represented by Z ²³ or Z ²⁴ is preferably a benzene ring, a pyridine ring, a pyrazine ring, an imidazole ring or a pyrazole ring, more preferably Is a benzene ring, a pyridine ring or a pyrazole ring, more preferably a benzene ring or a pyridine ring.

The benzene ring and nitrogen-containing aromatic heterocycle represented by Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ may have a substituent, and examples of the substituent on the carbon atom include the substituent group A. The substituent group B is applicable as a substituent on the nitrogen atom.

  The substituent on the carbon atom is preferably an alkyl group, a fluoroalkyl group, an aryl group, a heterocyclic group, a dialkylamino group, a diarylamino group, an alkoxy group, an aryloxy group, a silyl group, a cyano group, or a halogen atom. An alkyl group, a fluoroalkyl group, an aryl group, an aryloxy group, a heterocyclic group, a diarylamino group, an alkoxy group, a cyano group, or a halogen atom, more preferably an alkyl group, an alkoxy group, an aryl group, an aryloxy group, A fluorine atom or a cyano group is more preferable.

The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. As said alkyl group, C1-C12 is preferable, For example, a methyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The fluoroalkyl group is preferably a trifluoromethyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and examples thereof include a methoxy group, a butyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The hetero ring group represents a substituted or unsubstituted nitrogen-containing aromatic hetero ring group having 6 to 10 carbon atoms, which may be condensed, such as a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, Examples thereof include a triazine ring and a carbazole ring, and a carbazole ring is preferable.
The diarylamino group represents a substituted or unsubstituted diarylamino group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a diphenylamino group, a ditoluylamino group, and a dinaphthylamino group.
The dialkylamino group represents a substituted or unsubstituted dialkylamino group having 2 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The dialkylamino group preferably has 2 to 12 carbon atoms. Specifically, for example, a dimethylamino group, a diethylamino group, a dioctylamino group, a didecylamino group, a didodecylamino group, a dit-butylamino group, a dit -An amylamino group, a di s-butylamino group, etc. are mentioned.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
As the halogen atom, a fluorine atom is preferable.

Among these, from the viewpoint of aspect ratio, the above-mentioned substituent having a linear alkyl group and a linear alkyl group as a substituent is preferable.
The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of increasing the wavelength, an electron donating group and an aromatic ring group are preferable, for example, an alkyl group, a dialkylamino group, an alkoxy group, an aryl group, An aromatic heterocyclic group or the like is selected. In order to shorten the wavelength, an electron withdrawing group is preferable, and for example, a fluorine atom, a cyano group, a trifluoroalkyl group, and the like are selected.

  The substituent on the nitrogen atom is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex.

The substituents on Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ may be linked to form a condensed ring. Examples of the ring formed include a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, and a pyrimidine. And a ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a thiophene ring, and a furan ring. When the substituents of Z ²³ and Z ²⁴ are linked to each other, the platinum complex represented by the general formula (C-2) becomes a Pt complex of a cyclic tetradentate ligand.

  Of the platinum complexes represented by the general formula (C-2), one of the more preferable embodiments is a platinum complex represented by the following general formula (C-3).

In the formula, A ^{301 to} A ³¹³ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ³¹ represents a single bond or a divalent linking group. Y, Z, and M each independently represent a carbon atom or a nitrogen atom, and either one of Z and Y is a nitrogen atom.

General formula (C-3) is demonstrated.
L ³¹ has the same meaning as L ²¹ in formula (C-2), and the preferred range is also the same.

A ^{301 to} A ³⁰⁶ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied.
A ^{301 to} A ³⁰⁶ are preferably C—R, and Rs may be connected to each other to form a ring. When A ^{301 to} A ³⁰⁶ are C—R, R in A ³⁰² and A ³⁰⁵ is preferably a hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, heterocyclic group, dialkylamino group, diarylamino group , An alkoxy group, an aryloxy group, a silyl group, a cyano group, or a halogen atom, a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a heterocyclic group, a diarylamino group, an alkoxy group, a cyano group, or A halogen atom is more preferable, a hydrogen atom, an alkyl group, an alkoxy group, or a cyano group is further preferable, and a hydrogen atom is particularly preferable. The alkyl group and aryl group may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a halogen atom, and a fluoroalkyl group. -6 alkyl group, cyano group, amino group, halogen atom, fluoroalkyl group (preferably trifluoromethyl group), more preferably C1-6 alkyl group, halogen atom (preferably fluorine atom). is there. In the case where A ³⁰² and A ³⁰⁵ are C—R, R in the A ³⁰² and A ³⁰⁵ is preferably an aryl group from the viewpoint of improving the durability of the device, and a hydrogen atom or an alkyl group from the viewpoint of a short emission wavelength. An amino group, an alkoxy group, a fluorine atom, and a cyano group are preferable.
R in A ³⁰¹ , A ³⁰³ , A ³⁰⁴ and A ³⁰⁶ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom or an amino group. Group, an alkoxy group, an aryloxy group and a fluorine atom, and particularly preferably a hydrogen atom.

A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group, a dialkylamino group, a diaryl. An amino group, an alkyloxy group, a cyano group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a dialkylamino group, a cyano group, a fluorine atom, still more preferably a hydrogen atom, An alkyl group, a trifluoromethyl group, and a fluorine atom; If possible, the substituents may be linked to form a condensed ring structure. When shifting the emission wavelength to the short wavelength side, A ³⁰⁸ is preferably a nitrogen atom.

In the general formula (C-3), the 6-membered ring formed from two carbon atoms and A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ includes a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine. A ring, more preferably a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring and a pyridazine ring, and particularly preferably a benzene ring and a pyridine ring. When the 6-membered ring is a pyridine ring, a pyrazine ring, a pyrimidine ring, or a pyridazine ring (particularly preferably a pyridine ring), a hydrogen atom present at a position where a metal-carbon bond is formed as compared with a benzene ring. Since acidity improves, it is advantageous at the point which becomes easier to form a metal complex.

A ³¹¹ , A ³¹² and A ³¹³ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ³¹¹ , A ³¹² and A ³¹³ are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a heterocyclic group, a dialkylamino group, a diarylamino group, an alkoxy group. , Aryloxy group, cyano group, halogen atom, more preferably hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, dialkylamino group, cyano group, fluorine atom, more preferably hydrogen atom, alkyl group , A trifluoromethyl group and a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure.
At least one of A ³¹¹ , A ³¹² and A ³¹³ is preferably a nitrogen atom, and particularly preferably A ³¹¹ is a nitrogen atom.

  Of the platinum complexes represented by the general formula (C-3), one of more preferable embodiments is a platinum complex represented by the following general formula (C-3-1).

In the formula, X, Y, Z and M each independently represent a carbon atom or a nitrogen atom. However, one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. m, n, p, and q each independently represent an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group. R _{1 to} R ₃ and R ₃₀ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group. When m, n, p, and q are 2 or more, a plurality of R ₁ , R ₂ , R _3, and R ₃₀ may be connected to each other to form a cyclic structure. Q is a carbon atom or a nitrogen atom.

General formula (C-3-1) is demonstrated.
X, Y, and Z represent a carbon atom or a nitrogen atom, and any one of Z and Y is a nitrogen atom, and when Y is a nitrogen atom, X is a carbon atom. Preferably, Z is a carbon atom, Y is a nitrogen atom, and X is a carbon atom.
m, n and p each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, and more preferably 0 to 1. n is preferably 0 to 2, and more preferably 0 to 1. p is preferably 0 to 2, and more preferably 0 to 1.

R _{1 to} R ₃ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms, and specific examples include a methyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a hydrocarbon group having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. . The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
Among these, from the viewpoint of aspect ratio, in the case of a linear alkyl group or a group other than an alkyl group, it is preferable to have an alkyl group as a substituent.
R ₁ and R ₂ are preferably an alkyl group, an aryl group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an aryl group, and a phenyl group.
R ₃ is preferably an alkyl group or an aryl group, more preferably a methyl group, a trifluoromethyl group, or a phenyl group, and even more preferably a methyl group or a trifluoromethyl group.

Examples of the aryl group represented by Ar include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by Ar may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. Are an alkyl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group (preferably a trifluoromethyl group), and more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom. Ar is more preferably a phenyl group having a substituent, and the substituent is preferably a methyl group, a t-butyl group, a 4-pentyl-cyclohexyl group, a 4-pentyl-cyclohexylmethoxy group, or the like.
When m, n, and p are 2 or more, a plurality of R _{1 to} R ₃ may be connected to each other next to each other to form a cyclic structure.
M and Q are each independently a carbon atom or a nitrogen atom.
q represents an integer of 0 to 3, and an integer of 0 to 2 is preferable.

R ₃₀ represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl group, t-amyl group, s- A butyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, and may be condensed, and specifically includes a phenyloxy group, a toluyloxy group, a naphthyloxy group, and the like. Can be mentioned.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
R ₃₀ is preferably a fluorine atom.
From the viewpoint of aspect ratio, R ₃₀ preferably has an alkyl group as a substituent in the case of a chain alkyl group or a group other than an alkyl group.

  Among the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-4).

In the formula, A ^{401 to} A ⁴¹⁴ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁴¹ represents a single bond or a divalent linking group.

General formula (C-4) is demonstrated.
A ^{401 to} A ⁴¹⁴ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied.
A ^{401 to} A ⁴⁰⁶ are preferably C—R, and Rs may be connected to each other to form a ring. When A ^{401 to} A ⁴⁰⁶ are C—R, R in A ⁴⁰² and A ⁴⁰⁵ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, or a cyano group. More preferred are a hydrogen atom, an alkyl group, an amino group, an alkoxy group, an aryloxy group, and a fluorine atom, and particularly preferred are a hydrogen atom and an alkyl group. R in A ⁴⁰¹ , A ⁴⁰³ , A ⁴⁰⁴ and A ⁴⁰⁶ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom or an amino group. Group, an alkoxy group, an aryloxy group and a fluorine atom, and particularly preferably a hydrogen atom.
L ⁴¹ has the same meaning as L ²¹ in formula (C-2), and the preferred range is also the same.

As A ^{407 to} A ⁴¹⁴ , the number of nitrogen atoms in each of A ^{407 to} A ⁴¹⁰ and A ^{411 to} A ⁴¹⁴ is preferably 0 to 2, and more preferably 0 to 1.
When A ^{407 to} A ⁴¹⁴ represent C—R, R in A ⁴⁰⁸ and A ⁴¹² is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom. A cyano group, more preferably a hydrogen atom, a trifluoroalkyl group, an alkyl group, an aryl group, a fluorine atom or a cyano group, and particularly preferably a hydrogen atom, a phenyl group, a trifluoroalkyl group or a cyano group. . R in A ⁴⁰⁷ , A ⁴⁰⁹ , A ⁴¹¹ and A ⁴¹³ is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably Is a hydrogen atom, a trifluoroalkyl group, a fluorine atom or a cyano group, particularly preferably a hydrogen atom, a phenyl group or a fluorine atom. R in A ⁴¹⁰ and A ⁴¹⁴ is preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. When any of A ^{407 to} A ⁴⁰⁹ and A ^{411 to} A ⁴¹³ represents C—R, Rs may be connected to each other to form a ring. Examples of the ring formed include a benzene ring and pyridine. A ring is mentioned.

  Of the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-5).

In the formula, A ^{501 to} A ⁵¹² each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁵¹ represents a single bond or a divalent linking group. Y and Z each independently represent a carbon atom or a nitrogen atom, and at least one is a nitrogen atom.

General formula (C-5) is demonstrated. A ^{501 to} A ⁵⁰⁶ and L ⁵¹ have the same meanings as A ^{401 to} A ⁴⁰⁶ and L ⁴¹ in the general formula (C-4), and preferred ranges thereof are also the same.

A ⁵⁰⁷ , A ⁵⁰⁸ , A ⁵⁰⁹ , A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ⁵⁰⁷ , A ⁵⁰⁸ , A ⁵⁰⁹ , A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group. , Dialkylamino group, diarylamino group, alkyloxy group, cyano group, halogen atom, more preferably hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, dialkylamino group, cyano group, fluorine atom, Preferably, they are a hydrogen atom, an alkyl group, a trifluoromethyl group, or a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure.
An embodiment in which at least one of A ⁵⁰⁷ , A ⁵⁰⁸ , and A ⁵⁰⁹ , and at least one of A ⁵¹⁰ , A ^511, and A ⁵¹² is a nitrogen atom is also preferable. In this embodiment, A ⁵¹⁰ or A ⁵⁰⁷ is A nitrogen atom is preferred.

  Of the platinum complexes represented by the general formula (C-5), one of more preferable embodiments is a platinum complex represented by the following general formula (C-5-1).

In the formula, X, Y, and Z each independently represent a carbon atom or a nitrogen atom. However, one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. m, n, p, and q each independently represent an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group. R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group. When m, n, p, and q are 2 or more, the plurality of R _{1 to} R ₄ may be connected to each other to form a cyclic structure.

General formula (C-5-1) is demonstrated.
X, Y, and Z represent a carbon atom or a nitrogen atom, and any one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. Preferably, Z is a carbon atom, Y is a nitrogen atom, and X is a carbon atom.
m, n, p, and q each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, and more preferably 0 to 1. n is preferably 0 to 2, and more preferably 0 to 1. p is preferably 0 to 2, and more preferably 0 to 1. q is preferably 0 to 2, and more preferably 0 to 1.

R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. As said alkyl group, C1-C12 is preferable, and, specifically, a methyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group etc. are mentioned, for example.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a hydrocarbon group having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. . The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
Among these, from the viewpoint of aspect ratio, in the case of a linear alkyl group or a group other than an alkyl group, it is preferable to have an alkyl group as a substituent.
R ₁ and R ₂ are preferably an alkyl group, an aryl group, a fluorine atom, a cyano group, or a silyl group, and more preferably an alkyl group or an aryl group.
R ₃ and R ₄ are preferably an alkyl group or an aryl group, more preferably a methyl group, a trifluoromethyl group, or a phenyl group, and even more preferably a methyl group or a trifluoromethyl group.

Examples of the aryl group represented by Ar include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by Ar may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. Alkyl group, cyano group, amino group, fluorine atom and fluoroalkyl group (preferably trifluoromethyl group), more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom. Ar is more preferably a phenyl group having a substituent, and the substituent is preferably a methyl group, a t-butyl group, a 4-methyl-cyclohexyl group, or the like.
When m, n, p, q is 2 or more, a plurality of R _{1 to} R ₄ may be connected to each other adjacent to each other to form a cyclic structure.

  Of the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-6).

In the formula, X, Y, and Z each independently represent a carbon atom or a nitrogen atom. However, one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. r, s, t, and u each independently represent an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group. When r, s, t, and u are 2 or more, the plurality of R _{5 to} R ₈ may be linked to each other to form a cyclic structure. W ₁ and W ₂ each independently represent an alkyl group, and may be bonded to each other to form a cyclic structure.

General formula (C-6) is demonstrated.
X, Y, and Z are synonymous with X, Y, and Z of general formula (C-5-1), and their preferable ranges are also the same.

R < ₅ > -R < ₈ > is synonymous with R < ₁ > -R < ₄ > of general formula (C-5-1).
R ₅ and R ₆ are preferably an alkyl group, an alkoxy group, an aryl group, a fluorine atom, or a cyano group.
The alkyl group represented by R ₅ and R ₆ is preferably a methyl group, a butyl group, an octyl group, a decyl group, a dodecyl group or the like, which may have a substituent.
The alkoxy group represented by R ₅ and R ₆ is preferably a decyloxy group.
The aryl group represented by R ₅ and R ₆ is preferably a phenyl group which may have a substituent, and the substituent is preferably an alkyl group, more preferably a propyl group or a butyl group.
R ₇ and R ₈ are preferably an alkyl group or an aryl group.

r, s, t, and u each independently represent an integer of 0 to 3. Among these, r is preferably 0 to 2, and more preferably 0 or 1. s is preferably 0 to 2, more preferably 0 or 1. t is preferably 0 or 1, and u is preferably 0 or 1.
When r, s, t, u is 2 or more, the plurality of R _{5 to} R ₈ may be connected to each other adjacent to each other to form a cyclic structure. Examples of the cyclic structure include a structure that forms a fluorene ring together with a benzene ring, a benzofuran ring, and a 6-membered ring having Z.

W ₁ and W ₂ represent an alkyl group having 1 to 10 carbon atoms and may be bonded to each other to form a cyclic structure.
Examples of the alkyl group represented by W ₁ and W ₂ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a pentyl group, and a methyl group is preferable.
Examples of the cyclic structure formed by combining W ₁ and W ₂ include a cyclohexyl cyclic structure.
W ₁ and W ₂ are preferably a methyl group from the viewpoint of a high aspect ratio or are bonded to each other to form a cyclohexyl ring structure.

  Among the platinum complexes represented by the general formula (C-1), another more preferable embodiment is a platinum complex represented by the following general formula (C-7).

In the formula, L ⁶¹ represents a single bond or a divalent linking group. A ⁶¹ represents a carbon atom or a nitrogen atom. Z ⁶¹ and Z ⁶² each independently represent a nitrogen-containing aromatic heterocycle. Z ⁶³ represents a benzene ring or an aromatic heterocycle. Q is an anionic acyclic ligand that binds to Pt.

General formula (C-7) is demonstrated.
L ⁶¹ represents a single bond or a divalent linking group, and a preferred range is the same as L ¹ in the general formula (C-1).

A ⁶¹ represents a carbon atom or a nitrogen atom. In view of the stability of the complex and the light emission quantum yield of the complex, A ⁶¹ is preferably a carbon atom.

Z ⁶¹ and Z ⁶² are synonymous with Z ²¹ and Z ²² in the general formula (C-2), respectively, and preferred ranges thereof are also the same. Z ⁶³ has the same meaning as Z ²³ in formula (C-2), and the preferred range is also the same.

Q is an anionic acyclic ligand that binds to Pt. An acyclic ligand is one in which atoms bonded to Pt do not form a ring in the form of a ligand. As an atom couple | bonded with Pt in Q, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, a nitrogen atom and an oxygen atom are more preferable, and an oxygen atom is the most preferable.
Examples of Q bonded to Pt by a carbon atom include a vinyl ligand. Examples of Q bonded to Pt with a nitrogen atom include an amino ligand and an imino ligand. Q bonded to Pt with an oxygen atom includes an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, a carboxyl ligand, a phosphate ligand, Examples thereof include sulfonic acid ligands. Examples of Q bonded to Pt with a sulfur atom include alkyl mercapto ligands, aryl mercapto ligands, heteroaryl mercapto ligands, and thiocarboxylic acid ligands.
The ligand represented by Q may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other.

  The ligand represented by Q is preferably a ligand bonded to Pt with an oxygen atom, more preferably an acyloxy ligand, an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, A silyloxy ligand, more preferably an acyloxy ligand.

  Of the platinum complexes represented by the general formula (C-7), one of more preferred embodiments is a platinum complex represented by the following general formula (C-8).

In the formula, A ^{701 to} A ⁷¹⁰ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁷¹ represents a single bond or a divalent linking group. Q is an anionic acyclic ligand that binds to Pt.

General formula (C-8) is demonstrated.
L ⁷¹ has the same meaning as L ^{61 in} formula (C-6), and the preferred range is also the same. A ^{701 to} A ⁷¹⁰ have the same meanings as A ^{401 to} A ⁴¹⁰ in formula (C-4), and preferred ranges thereof are also the same. Y has the same meaning as that in formula (C-6), and the preferred range is also the same.

  Among the platinum complexes represented by the general formula (C-1), one of other preferable embodiments is a platinum complex represented by the following general formula (C-9).

In the formula, A and B represent a cyclic structure, A represents an aromatic ring, and B represents an aromatic heterocycle. When one of A and B forms a ring, the other may not form a ring. R _{13 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ are bonded to each other to form a cyclic structure. It may be formed.

General formula (C-9) is demonstrated.
A represents an aromatic ring. Examples of the aromatic ring include an aromatic hydrocarbon ring and an aromatic heterocycle, and an aromatic hydrocarbon ring is preferable. As the aromatic hydrocarbon ring represented by A, a benzene ring and a naphthalene ring are preferable. As the aromatic heterocycle represented by A, a pyridine ring, a pyrazine ring, a pyrimidine ring and a quinoline ring are preferable.
B represents an aromatic heterocycle. The aromatic heterocycle represented by B is preferably a pyridine ring or a pyrimidine ring.
As a combination of A and B, it is preferable that A is a benzene ring and B is a non-ring (does not form a ring), A is a naphthalene ring and B is a non-ring, and A is a benzene ring and B is a pyridine ring, or More preferably, A is a non-ring and B is a pyridine ring.
R _{13 to} R ₁₆ represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₁₄ and R ₁₅ , or R ₁₃ and R ₁₆ may be bonded to each other to form a cyclic structure. .
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. As said alkyl group, C1-C12 is preferable, for example, a methyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. As said silyl group, C3-C18 is preferable and a trimethylsilyl group, t-butyldimethylsilyl group, a triphenylsilyl group, t-butyldiphenylsilyl group, etc. are mentioned.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.

R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each preferably a substituted or unsubstituted aryl group, or an aromatic ring in which R ₁₃ and R ₁₆ , and R ₁₄ and R ₁₅ are bonded to each other. Examples of the aromatic ring include a benzene ring. The aromatic ring may further have a substituent, for example, an alkyl group (methyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group), alkoxy group (methoxy group, ethoxy group, butoxy group). Etc.).
Among these, an aromatic ring in which R ₁₃ and R ₁₆ , R ₁₄ and R ₁₅ are bonded to each other is preferable from the viewpoint of aspect ratio and molecular size.

  As a more preferable aspect of the compound represented by general formula (C-9), the compound of the following general formula (C-9-1) is mentioned.

In the formula, B may form an aromatic 6-membered heterocycle.
R _{17 to} R ₂₆ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and R ₁₇ and R ₁₈ , R ₁₈ and R ₁₉ , R ₁₉ and R ₂₀ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ may be bonded to each other to form a cyclic structure. Preferred examples of the alkyl group, aryl group, alkoxy group, aryloxy group, cyano group, silyl group, and heterocyclic group represented by R _{17 to} R ₂₆ are the same as the examples of each group represented by R _{13 to} R _26. .
R ₁₇ , R ₂₀ , R ₂₁ and R ₂₄ are preferably a hydrogen atom or an alkyl group.
R ₁₈ , R ₁₉ , R ₂₂ and R ₂₃ are preferably an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an alkoxy group, a decyloxy group or a dodecyl group. An oxy group is more preferable.
R _{25 to} R ₂₆ are preferably a hydrogen atom, an alkyl group, a fluorine atom, or an aromatic ring in which R ₂₅ and R ₂₆ are bonded.
The aromatic 6-membered heterocycle represented by B is preferably a pyridine ring or a pyrimidine ring, and more preferably a pyridine ring. The ring may have a substituent, and examples of the substituent include an alkyl group (methyl group and butyl group) and an aryl group (phenyl group).
From the viewpoint of the aspect ratio, R _{17 to} R ₂₆ preferably have an alkyl group as a substituent in the case of a chain alkyl group or a group other than an alkyl group.

  The platinum complex represented by the general formula (C-1) is preferably a platinum complex represented by any one of the general formulas (C-2), (C-7), and (C-9). The platinum complex represented by formula (C-2) or (C-9) is more preferable. The platinum complex represented by the general formula (C-2) is a platinum complex represented by any one of the general formulas (C-3), (C-4), (C-5), and (C-6). The platinum complex is more preferably a platinum complex represented by any one of the general formulas (C-3-1), (C-5-1), and (C-6). A platinum complex represented by -5-1) or (C-6) is particularly preferable.

Specific examples of the platinum complex represented by the general formula (C-1) include [0143] to [0152], [0157] to [0158], and [0162] to [0168] of JP-A-2005-310733. The compounds described in JP-A-2006-256999, [0065] to [0083], the compounds described in JP-A-2006-93542, [0065] to [0090], JP-A-2007-73891 Nos. [0063] to [0071], No. 2007-324309, No. 0079 to [0083], No. 2006-93542 No. [0065] to [0090] Compounds described in JP-A-2007-96255, [0055] to [0071], JP-A-2006-313796 0043] include compounds described in ~ [0046].
Examples of the platinum complex represented by the general formula (C-1) and other platinum complexes having an aspect ratio larger than 3 are given below. In addition, the alkyl group and the alkyl group in the exemplary compound include a linear alkyl group, a branched alkyl group, and a cycloalkyl group, and preferably a linear alkyl group.

Examples of the platinum complex represented by the general formula (C-1) include Journal of Organic Chemistry 53,786, (1988), G.S. R. Newkome et al. ), Page 789, method described in left column 53 to right column 7, line 790, method described in left column 18 to 38, method 790, method described in right column 19 to 30 and The combination, Chemische Berichte 113, 2749 (1980), H.C. Lexy et al.), Page 2752, lines 26-35, and the like.
For example, a ligand or a dissociated product thereof and a metal compound are mixed with a solvent (for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, In the presence of a sulfoxide solvent, water, etc., or in the absence of a solvent, in the presence of a base (inorganic and organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Or in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

[Pyrene derivatives]
Conventionally known pyrene derivatives can be used as the pyrene derivative, but a compound represented by the following general formula (P-1) (hereinafter also referred to as “compound (P-1)”) is preferably used. .

In the formula, R _P ^{1 to} R _P ¹⁰ each independently have a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, an alkyl group which may have a substituent, or a substituent. A silyl group which may have, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, or an arylamino group which may have a substituent, At least one of R _P ^{1 to} R _P ¹⁰ is a group other than a hydrogen atom.

_<R ^P 1 ~R ^{P 10>}
(Types of substituents R _P ^{1 to} R _P ¹⁰ )
R _P ^{1 to} R _P ¹⁰ may each independently have a hydrogen atom, an aromatic hydrocarbon group that may have a substituent, an alkyl group that may have a substituent, or a substituent. A good silyl group, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, and an arylamino group which may have a substituent are represented. These may be bonded to each other and condensed.
At least one of R _P ^{1 to} R _P ¹⁰ is a group other than a hydrogen atom.

When two or more of R _P ^{1 to} R _P ¹⁰ are groups other than hydrogen atoms, the groups other than the plurality of hydrogen atoms may be the same or different. It is preferable that they are the same in terms of ease of synthesis, and are preferably different in that the emission wavelength can be tuned.

In addition, in terms of obtaining high luminous efficiency, the groups other than the hydrogen atoms of R _P ^{1 to} R _P ¹⁰ may have an aromatic hydrocarbon group which may have a substituent or a substituent. A silyl group is preferable, and an aromatic hydrocarbon group which may have a substituent is particularly preferable. Moreover, in terms of obtaining light emission with a narrow half width, groups other than the hydrogen atoms of R _P ^{1 to} R _P ¹⁰ are an alkyl group which may have a substituent, and an arylamino which may have a substituent. Group, a heterocyclic group which may have a substituent is preferable, and R _P ¹ , R _P ^{3 to} R _P ⁶ , and R _P ^{8 to} R _P ¹⁰ are hydrogen atoms in that a long emission wavelength is obtained. As other groups, an aromatic hydrocarbon which may have a substituent and a heterocyclic group which may have a substituent are preferable.

The aromatic hydrocarbon group represented by R _P ^{1 to} R _P ¹⁰ is preferably an aromatic hydrocarbon group having 6 to 16 carbon atoms, and is not limited to a monocyclic group, and may be a condensed polycyclic hydrocarbon group. . Specific examples of the aromatic hydrocarbon group include phenyl group, biphenyl group, phenanthryl group, naphthyl group, anthryl group, and fluorenyl group.

As the alkyl group represented by R _P ^{1 to} R _P ¹⁰ , an alkyl group having 1 to 10 carbon atoms is preferable, and specific examples include i-propyl group, t-butyl group, cyclohexyl group and the like.
The silyl group preferably has 3 to 20 carbon atoms, and specific examples include trimethylsilyl group, dimethylphenylsilyl group, dimethylbutylsilyl group, triisopropylsilyl group, and methyldibutylsilyl group.
As the heterocyclic group represented by R _P ^{1 to} R _P ¹⁰ , those having 3 to 10 carbon atoms are preferable, and specific examples include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group. , Dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, imidazolyl group, phenylcarbazoyl group and the like.
The alkylamino group represented by R _P ^{1 to} R _P ¹⁰ is preferably an alkylamino group having 1 to 10 carbon atoms, and specific examples include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, and the like.
The arylamino group represented by R _P ^{1 to} R _P ¹⁰ is preferably an arylamino group having 6 to 30 carbon atoms, and specific examples thereof include a diphenylamino group, a carbazoyl group, and a phenylnaphthylamino group.

  The substituents that these groups may have include aryl groups, arylamino groups, alkyl groups, perfluoroalkyl groups, halide groups, carboxyl groups, cyano groups, alkoxyl groups, aryloxy groups, carbonyl groups, oxycarbonyls. Group, carboxylic acid group, heterocyclic group and the like. Preferably, an aryl group having 6 to 16 carbon atoms, an arylamino group having 12 to 30 carbon atoms, an alkyl group having 1 to 12 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, a fluoride group, and 1 to 10 carbon atoms. Oxycarbonyl groups, cyano groups, alkoxy groups having 1 to 10 carbon atoms, aryloxy groups having 6 to 16 carbon atoms, carbonyl groups having 2 to 16 carbon atoms, heterocyclic groups having 5 to 20 carbon atoms, and the like.

Among the substituents, examples of the aryl group having 6 to 16 carbon atoms include a phenyl group, a naphthyl group, and a phenanthryl group.
Examples of the arylamino group having 12 to 30 carbon atoms include a diphenylamino group, a carbazoyl group, and a phenylcarbazoyl group.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a butyl group, an i-propyl group, a neopentthiol group, and a t-butyl group.
A trifluoromethyl group etc. are mentioned as an example of a C1-C12 perfluoroalkyl group.
Examples of the oxycarbonyl group having 1 to 10 carbon atoms include a methoxycarbonyl group and an ethoxycarbonyl group.
Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group and an ethoxy group.
Examples of the aryloxy group having 6 to 16 carbon atoms include a phenyloxy group.
Examples of the carbonyl group having 2 to 16 carbon atoms include an acetyl group and a phenylcarbonyl group.
Examples of the heterocyclic group having 3 to 20 carbon atoms include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group, dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, imidazoyl Group and the like.
Among the substituents that R _P ^{1 to} R _P ¹⁰ and R _P ^{1 to} R _P ^{10 described above} may have, an electron donating group such as an arylamino group and an alkoxy group, a thienyl group, and a benzothienyl group And the like contribute to the increase in the emission wavelength of the compound (P-1). Thus the substituent that may be _R ^P 1 _~R ^{P 10} and _R ^P 1 _~R ^{P 10} has, by selecting these substituents, can be obtained that exhibit a green light emission.

Of the compounds (P-1), particularly preferred are the following general formulas (P-1a), (P-1b), (P-1c), (P-1d), or (P-1e). It is a compound represented by these. In the general formulas (P-1a), (P-1b), (P-1c), (P-1d), and (P-1e), R _P ^{1 to} R _P ¹⁰ are R in the general formula (P-1). it is synonymous with _P ¹ _{~R P} ^10. Further, R _P ¹ and R _P ² , R _P ⁶ and R _P ⁷ in the general formula (P-1c), R _P ¹ and R _P ¹⁰ , R _P ⁵ and R _P ⁶ in the general formula (P-1d), R _P ⁹ and R _P ¹⁰ , R _P ⁴ and R _P ⁵ in the general formula (P-1e) are bonded to each other to form a ring. The ring formed here is preferably a 5- or 6-membered ring.

  Specific examples of pyrene derivatives that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The pyrene derivatives represented by the general formulas (P-1a) to (P-1e) can be synthesized according to the following scheme.

In the above scheme, R P 1 ~R P 10 has the same meaning as R P 1 ~R P 10 in the general formula (P-1). X represents a halogen atom.

[Perylene derivatives]
As the perylene derivative, a conventionally known perylene derivative can be used, but a compound represented by the following general formula (PE-1) is preferably used.

In the formula, R _PE ^{1 to} R _PE ⁴ are each independently an alkyl group, an aryl group, a heterocyclic group, an amino group, a silyl group, an ester group, an amide group, an alkoxy group, an aryloxy group, a heteroaryloxy group, An alkylthio group and an arylthio group are represented, and these may further have a substituent. These may be bonded to each other to form a ring.
n _PE ¹ ~n _PE ⁴ each independently represents an integer of 0 to 3. When n _PE ^{1 to} n _PE ⁴ is 2 or more, the plurality of R _PE ^{1 to} R _PE ⁴ may be bonded to each other to form a ring.
Further, the hydrogen atom in the formula may be a deuterium atom.

R _PE ^{1 to} R _PE ⁴ are preferably an alkyl group, an aryl group, a heterocyclic group, an amino group, a silyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthio group or an arylthio group, and an alkyl group or an aryl group , A heterocyclic group, an amino group, and a silyl group are more preferable. These groups may have a substituent, and examples of the substituent include the groups mentioned in the above-mentioned substituent group A. In the case of having a plurality of substituents, the substituents may be linked to form a ring.
n _PE ¹ ~n _PE ⁴ is preferably 0-2, 0-1 is more preferable.

As the compound represented by the general formula (PE-1), a compound represented by any one of the following general formulas (PE-1a) to (PE-1f) is preferable.
In the general formulas (PE-1a) to (PE-1f), R _pe is independently an alkyl group, aryl group, heterocyclic group, amino group, silyl group, ester group, amide group, alkoxy group, aryloxy Represents a group, a heteroaryloxy group, an alkylthio group, or an arylthio group. These may further have a substituent. Furthermore, R _pe in the general formulas (PE-1d) to (PE-1f) independently form a 5-membered or 6-membered ring, and the ring may further have a substituent.
Further, the hydrogen atoms in the general formulas (PE-1a) to (PE-1f) may be deuterium atoms.

_Rpe is preferably an alkyl group (such as a methyl group, a propyl group, or a butyl group), an aryl group (such as a phenyl group or a naphthyl group), a heterocyclic group (such as a pyridyl group), an amino group, a silyl group, or an amide group. It is.
_Examples of the substituent that the ring formed by R _pe and R _pe may have include an alkyl group (such as a methyl group and a butyl group) and an aryl group (such as a phenyl group).

  Specific examples of perylene derivatives that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The perylene derivative represented by the general formula (PE-1) can be synthesized according to the following scheme.

In the above scheme, R _pe has the same _{meaning as} R _PE ^{1 to} R _PE ⁴ in formula (PE-1). X represents a halogen atom.

[Π-Conjugated Compound Represented by General Formula (R-1)]
The π-conjugated compound represented by the general formula (R-1) will be described. The compound does not exhibit a clear melting point, has a glass transition point of 60 ° C. or higher, has a molecular weight in the range of 400 to 2500, and is a charge transporting amine-based π-conjugated compound, The ratio (L / D) of the length (L) to the diameter (D) of the inscribed minimum diameter cylinder is 2.5 or more.

(Here, Ar _{1 to} Ar ₃ each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and Ar _{4 to} Ar ₇ each independently represents an aromatic carbon atom having 6 to 30 carbon atoms. Represents a hydrogen group, and two aromatic hydrocarbon groups constituting Ar ₄ and Ar ₅ are bonded directly or via a substituent to form a condensed heterocyclic ring with N substituted by Ar ₄ and Ar _5. Alternatively, two aromatic hydrocarbon groups constituting Ar ₆ and Ar ₇ may be bonded directly or through a substituent to form a condensed heterocyclic ring with N substituted by Ar ₆ and Ar _7. L ₁ and L ₂ each independently represents a vinylene group or an acetylene group, and l, m, n, o and p each independently represent an integer of 0 to 6, but any one of l, n and p One is not 0.)

  Examples of the π-conjugated compound represented by the general formula (R-1) include a π-conjugated compound represented by the following general formula (R-2) or (R-3).

(Here, Ar _{1 to} Ar ₃ , L ₁ , L ₂ and _{1 to} p have the same meaning as in the general formula (R-1). R ^s each independently represents a substituent. Q represents each. Independently represents an integer of 0 to 5.)

(Here, Ar ₂ has the same meaning as in the general formula (R-1). R ^s each independently represents a substituent. Q independently represents an integer of 0 to 5.)

  The π-conjugated compound represented by the general formula (R-1) does not show a clear melting point, has a glass transition point of 60 ° C. or higher, has a molecular weight in the range of 400 to 2500, and has a charge transporting amine type. It is a π-conjugated compound. The ratio (L / D) of the length (L) to the diameter (D) of the cylinder with the smallest diameter inscribed by this π-conjugated compound is 2.5 or more. Here, (L / D) is a numerical value that defines the length of the molecule of the π-conjugated compound. In the case of an elongated molecule, the effect of controlling the orientation is great. Therefore, (L / D) is preferably in the range of 3-10. The amine-based conjugated compound is preferably a compound having an amino group or an N-heterocyclic group at the end of the compound skeleton (aromatic ring-containing skeleton). Among the compounds represented by the general formula (R-1), there are compounds represented by the general formula (R-2) and the general formula (R-3).

The amino group is preferably an aromatic amino group represented by —N (Ar) ₂ (wherein Ar is an aromatic group). The N-heterocyclic group is a cyclic amino group, and an N-heterocyclic group such as an N-carbazolyl group, an N-phenoxazinyl group, or an N-phenothiazinyl group bonded to the terminal of the compound skeleton with an N atom is preferable.

In General Formula (R-1), Ar _{1 to} Ar ₃ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and Ar _{4 to} Ar ₇ each independently represent 6 to 6 carbon atoms. represents an 30 aromatic hydrocarbon group, Ar ₄ and Ar ₅ and,, Ar ₆ and Ar _{7 are} two aromatic hydrocarbon group constituting Ar 4 to Ar ₇ is via a direct bond or a substituent bonded Then, a condensed heterocyclic ring may be formed by Ar ₄ and Ar ₅ and Ar ₆ and N substituted by Ar ₇ . Further, -NAr ₆ Ar ₇ or -NAr ₆ and Ar ₇ may form a cyclic amino group. Here, the condensed heterocyclic ring is understood as a structure having a heterocyclic ring containing N at the center and an aromatic hydrocarbon group condensed on both sides thereof. Specific examples include an N-carbazolyl group, but are not limited to three rings and may be four or more rings and may have a substituent.
L ₁ and L ₂ each independently represents a vinylene group or an acetylene group.
l, m, n, o and p each independently represent an integer of 0 to 6, but any one of l, n and p is not 0. The total of l, m, n, o and p is preferably in the range of 2 to 10, which is related to the (L / D). Further, when l, m, n, o, or p is an integer greater than 6, the molecular weight of the π-conjugated compound is increased, so that vapor deposition is difficult. Therefore, preferably, l, m, n, o, and p is an integer of 0 to 3, and any one of l, n, and p is preferably an integer that is not 0.

  The π-conjugated compound preferably has a ratio (L / D) of 2.5 or more of the length (L) and the diameter (D) of the cylinder with the smallest diameter inscribed by the molecules of the π-conjugated compound. When L / D becomes large, the molecular weight of the π-conjugated compound becomes large, which makes it difficult to form a film by vapor deposition. Preferably they are 2.5 or more and 10.0 or less, Especially preferably, they are 2.5 or more and 5.0 or less.

  Among the compounds represented by general formula (R-1), preferred compounds include compounds represented by general formula (R-2) and general formula (R-3).

In the general formula _{(R-2), Ar 1} ~Ar 3, L 1, L 2 and l~p includes _{Ar 1 ~Ar 3, L 1,} L 2 and l~p in the general formula (R-1) Have the same meaning. In General Formula (R-3), Ar ₂ has the same meaning as Ar ₂ in General Formula (R-1).
In the general formulas (R-2) and (R-3), R ^s independently represents a substituent, and as the substituent, those exemplified as the substituent group A can be appropriately applied. The substituent represented by R ^s is preferably an alkyl group.
Each q independently represents an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0 or 1.

In General Formula (R-1), Ar _{1 to} Ar ₃ are divalent hydrocarbon-based aromatic groups generated by taking two hydrogen atoms from a hydrocarbon-based aromatic compound having 6 to 30 carbon atoms; _{4 to} Ar ₇ is a monovalent hydrocarbon-based aromatic group generated by taking one hydrogen from a hydrocarbon-based aromatic compound having 6 to 30 carbon atoms. As such a hydrocarbon-based aromatic compound, In addition to benzene, biphenyl, and terphenyl, condensed ring structures such as naphthalene, anthracene, tetracene, phenanthrene, chrysene, coronene, and fluorene can be exemplified. Although the example of the aromatic hydrocarbon compound which gives the said hydrocarbon-type aromatic group is shown below, it is not limited to these. Although the example shown below is an example which does not have a substituent, if a carbon number is the said range, it can have a substituent like an alkyl group.

  The π-conjugated compound does not exhibit a clear melting point and exhibits a glass transition point of 60 ° C. or higher. A preferable Tg is 60 to 300 ° C., and if it is Tg exceeding this temperature, a large apparatus load is required to control the substrate temperature during vapor deposition and film formation is performed on the substrate. Further, it is not preferable because sublimation of the π-conjugated compound occurs. The molecular weight of the π-conjugated compound is in the range of 400 to 2500, and preferably in the range of 400 to 1000. When this molecular weight is exceeded, vapor deposition film formation becomes difficult.

  Specific examples of the π-conjugated compound represented by the general formula (R-1) are shown below, but are not limited thereto.

  The fluorescent material in the present invention is preferably a pyrene derivative represented by the above general formulas (P-1a) to (P-1d) and a π-conjugated compound represented by the above general formula (R-1), and the compound 128 described above. Highly symmetric pyrene derivatives such as 129 and 133-179 and π-conjugated compounds represented by the above general formula (R-1) are more preferred, and π-conjugated compounds represented by the specific examples described above are particularly preferred. The pyrene derivative described above and the π-conjugated compound described above can realize a high degree of orientation (S).

  Although the thickness of the light emitting layer is not particularly limited, it is usually preferably 2 nm to 500 nm, more preferably 3 nm to 200 nm, and more preferably 5 nm to 100 nm from the viewpoint of external quantum efficiency. More preferably.

The light emitting layer in the element of the present invention may be composed of only a light emitting material, or may be a mixed layer of a host material and a light emitting material. The light emitting material may be one kind or two or more kinds. The host material is preferably a charge transport material. The host material may be one kind or two or more kinds, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed.
Furthermore, the light emitting layer may include a material that does not have charge transporting properties and does not emit light.
The light emitting layer may be a single layer or a multilayer of two or more layers. In addition, each light emitting layer may emit light with different emission colors.
In the light emitting layer, the host material other than the light emitting material is preferably a flat plate material.

  The content of the light emitting material in the light emitting layer of the present invention is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 25% by mass, and particularly preferably 5% by mass to 20% by mass.

<Host material>
The light emitting layer preferably further contains a host material. The host material may be a hole transporting host material or an electron transporting host material, but a hole transporting host material can be used.
The host material used in the present invention may contain the following compounds. For example, pyrrole, indole, carbazole (eg, CBP (4,4′-di (9-carbazoyl) biphenyl)), azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole, imidazole, thiophene, polyarylalkane, Pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine compound, porphyrin compound, polysilane compound, poly (N-vinyl) Carbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organic silane, carbon film, pyridine, pyrimidine, triazine, imidazo , Pyrazole, triazole, oxazole, oxadiazol, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, fluorine-substituted aromatic compounds , Metal complexes of heterocyclic tetracarboxylic anhydrides such as naphthalene and perylene, metal complexes of phthalocyanine and 8-quinolinol derivatives and metal complexes having metal phthalocyanine, benzoxazole and benzothiazole as ligands Examples include complexes and derivatives thereof (which may have a substituent or a condensed ring), aromatic hydrocarbon compounds such as triphenylene derivatives, and the like.
The host material in the present invention is preferably a flat host material from the viewpoint of the orientation of the light emitting material, more preferably a carbazole compound or a triphenylene derivative as described later, and further preferably a triphenylene derivative.

In the light emitting layer of the present invention, the host material triplet minimum excitation energy (T ₁ energy) is preferably higher than the T ₁ energy of the light emitting material in terms of color purity, light emission efficiency, and driving durability.

  Further, the content of the host material in the light emitting layer of the present invention is not particularly limited, but from the viewpoints of light emission efficiency and driving voltage, it is 15% by mass or more and 95% by mass with respect to the total compound mass forming the light emitting layer. % Or less is preferable.

  In the present invention, the host material preferably contains at least one compound represented by the general formula (4-1) or (4-2) which is a carbazole compound.

  The compound represented by the general formula (4-1) or (4-2) is preferably contained in the light emitting layer in an amount of 30 to 99% by mass, more preferably 40 to 97% by mass, and 50 to 95% by mass. % Is particularly preferable. Moreover, when using the compound represented by general formula (4-1) or (4-2) for a some organic layer, it is preferable to contain in said layer in each layer.

  The compound represented by the general formula (4-1) or (4-2) may contain only one kind in any organic layer, and a plurality of general formulas (4-1) or (4 The compound represented by -2) may be contained in combination at any ratio.

  The host material is preferably a compound represented by the following general formula (4-1) or (4-2).

(In General Formulas (4-1) and (4-2), d and e each represent an integer of 0 to 3, at least one of which is 1 or more. F represents an integer of 1 to 4. R ⁸ is substituted. When a plurality of R ⁸ are present, R ⁸ may be different or the same, and at least one of R ⁸ represents a carbazole group represented by the following general formula (5).

(In General Formula (5), each R ₉ independently represents a substituent. G represents an integer of 0 to 8.)

R ⁸ each independently represents a substituent, specifically, a halogen atom, an alkoxy group, a cyano group, a nitro group, an alkyl group, an aryl group, a heterocyclic group, or a substituent represented by the general formula (5). is there. When R ⁸ does not represent the general formula (5), it is preferably an alkyl group having 10 or less carbon atoms, a substituted or unsubstituted aryl group having 10 or less carbon atoms, and more preferably an alkyl group having 6 or less carbon atoms. is there.

R ₉ each independently represents a substituent, specifically a halogen atom, an alkoxy group, a cyano group, a nitro group, an alkyl group, an aryl group, or a heterocyclic group, preferably an alkyl group having 10 or less carbon atoms, a carbon group It is a substituted or unsubstituted aryl group having several tens or less, and more preferably an alkyl group having six or fewer carbon atoms.
g represents an integer of 0 to 8, and is preferably 0 to 4 from the viewpoint of not excessively shielding the carbazole skeleton responsible for charge transport. From the viewpoint of ease of synthesis, when carbazole has a substituent, those having a substituent so as to be symmetric with respect to the nitrogen atom are preferable.

In the general formula (4-1), the sum of d and e is preferably 2 or more from the viewpoint of maintaining the charge transport ability. Further, R ⁸ is preferably substituted with meta for the other benzene ring. The reason for this is that in ortho substitution, the steric hindrance between adjacent substituents is large, so that the bond is easily cleaved, and the durability is lowered. In addition, in para substitution, the molecular shape approaches a rigid rod shape and is easily crystallized, so that element degradation is likely to occur under high temperature conditions. Specifically, a compound represented by the following structure is preferable.

In the above formula, ^{R 8} has the same meaning as ^{R 8} in the general formula (4-1), h and i are each independently 0 or 1, 0 is preferable.
R ₉ each independently represents a substituent. g represents an integer of 0 to 8.
The preferred ranges of R ₉ and g are the same as those in the above general formula (5).

In the general formula (4-2), f is preferably 2 or more from the viewpoint of maintaining the charge transport ability. When f is 2 or 3, it is preferable that R ⁸ is mutually substituted with meta from the same viewpoint. Specifically, a compound represented by the following structure is preferable.

In the above formula, each R ₉ independently represents a substituent. g represents an integer of 0 to 8.
The preferred ranges of R ₉ and g are the same as those in the above general formula (5).

When the general formulas (4-1) and (4-2) have a hydrogen atom, an isotope of hydrogen (such as a deuterium atom) is also included. In this case, all hydrogen atoms in the compound may be replaced with hydrogen isotopes, or a mixture in which a part is a compound containing hydrogen isotopes may be used. R ₉ in the general formula (5) is preferably substituted with deuterium, and the following structures are particularly preferable.

  Furthermore, the atom which comprises a substituent represents that the isotope is also included.

  The compounds represented by the general formulas (4-1) and (4-2) can be synthesized by combining various known synthesis methods. Most commonly, carbazole compounds are synthesized by dehydroaromatization after the Athercorp rearrangement reaction of a condensate of an aryl hydrazine and a cyclohexane derivative (LF Tieze, by Th. Eicher, translated by Takano, Ogasawara, Precision organic synthesis, page 339 (published by Nankodo). Regarding the coupling reaction of the obtained carbazole compound and halogenated aryl compound using a palladium catalyst, Tetrahedron Letters 39: 617 (1998), 39: 2367 (1998) and 40: 6393 (1999) and the like. The reaction temperature and reaction time are not particularly limited, and the conditions described in the above literature can be applied. Some compounds such as mCP which are commercially available can be preferably used.

  The compounds represented by the general formulas (4-1) and (4-2) of the present invention preferably form a thin layer by a vacuum deposition process, but a wet process such as solution coating can also be suitably used. . The molecular weight of the compound is preferably 2000 or less, more preferably 1200 or less, and particularly preferably 800 or less from the viewpoints of deposition suitability and solubility. Also, from the viewpoint of vapor deposition suitability, if the molecular weight is too small, the vapor pressure becomes small, the change from the gas phase to the solid phase does not occur, and it is difficult to form an organic layer. Particularly preferred.

  General formulas (4-1) and (4-2) are preferably the following structures or compounds in which one or more hydrogen atoms are substituted with deuterium atoms.

In the above formula, R ₈ and R ₉ each independently represents a substituent.

  Specific examples of the compounds represented by formulas (4-1) and (4-2) in the present invention are illustrated below, but the present invention is not limited to these.

Further, as the host material, a triphenylene derivative is also preferable, and a triphenylene derivative represented by the following general formula (Tp-1) (hereinafter sometimes simply referred to as “triphenylene derivative”) is preferable.
The triphenylene derivative represented by the general formula (Tp-1) consists of only carbon atoms and hydrogen atoms, and is excellent in terms of chemical stability. Therefore, driving durability is high, and various changes are unlikely to occur during high luminance driving. There is an effect.

  The triphenylene derivative represented by the general formula (Tp-1) preferably has a molecular weight in the range of 400 to 1200, more preferably 400 to 1000, and still more preferably 400 to 800. If the molecular weight is 400 or more, a high-quality amorphous thin film can be formed, and if the molecular weight is 1200 or less, it is preferable in terms of solubility in a solvent, sublimation, and appropriate deposition.

  The use of the triphenylene derivative represented by the general formula (Tp-1) is not limited, and the triphenylene derivative may be further contained not only in the light emitting layer but also in any layer in the organic layer.

(In the general formula (Tp-1), R ^{12 to} R ²³ are each independently substituted with a hydrogen atom, an alkyl group, or a cyano group, an alkyl group, a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group. A phenyl group, a fluorenyl group, a naphthyl group, a triphenylenyl group, or a group formed by a combination thereof, provided that R ^{12 to} R ²³ are not all hydrogen atoms.)

Examples of the alkyl group represented by R ^{12 to} R ²³ include a substituted or unsubstituted, for example, methyl group, ethyl group, isopropyl group, n-butyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like can be mentioned, preferably methyl group, ethyl group, isopropyl group, tert-butyl group, cyclohexyl group, more preferably methyl group, ethyl group, or A tert-butyl group.

R ^{12 to} R ²³ are preferably an alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group (these are further an alkyl group, a phenyl group, and a fluorenyl group). More preferably a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group, which may be substituted with a group, a naphthyl group, or a triphenylenyl group.
A benzene ring that may be substituted with a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group (which may be further substituted with an alkyl group, a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group); It is particularly preferred.

  The total number of aryl rings in the general formula (Tp-1) is preferably 2 to 8, and preferably 3 to 5. By setting it as this range, a high-quality amorphous thin film can be formed, and solubility in a solvent, sublimation, and deposition suitability are improved.

R ^{12 to} R ²³ each independently preferably has a total carbon number of 20 to 50, and more preferably a total carbon number of 20 to 36. By setting it as this range, a high-quality amorphous thin film can be formed, and solubility in a solvent, sublimation, and deposition suitability are improved.

  In one embodiment of the present invention, the triphenylene derivative represented by the general formula (Tp-1) is preferably a triphenylene derivative represented by the following general formula (Tp-2).

(In General Formula (Tp-2), a plurality of Ar ¹ are the same, and a phenyl group, a fluorenyl group, which may be substituted with a cyano group, an alkyl group, a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group, A naphthyl group, a triphenylenyl group, or a group formed by combining these is represented.)

As the alkyl group and alkyl group represented by Ar ¹ , a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group that may be substituted with a phenyl group, a fluorenyl group, a naphthyl group, or a triphenylenyl group, R ^{12 to} R ²³ It is synonymous with what was mentioned, and a preferable thing is also the same.

  In another aspect of the present invention, the triphenylene derivative represented by the general formula (Tp-1) is preferably a triphenylene derivative represented by the following general formula (Tp-3).

(In the general formula (Tp-3), L represents a cyano group, an alkyl group, a phenyl group, a fluorenyl group, a naphthyl group, or a phenyl group optionally substituted with a triphenylenyl group, a fluorenyl group, a naphthyl group, a triphenylenyl group, or (It represents an n-valent linking group formed by combining these, and n represents an integer of 1 to 6.)

The alkyl group, phenyl group, fluorenyl group, naphthyl group, or triphenylenyl group that forms the n-valent linking group represented by L has the same meaning as that described for R ^{12 to} R ²³ .
L is preferably an alkyl group or an n-valent linking group formed by combining a benzene ring, a fluorene ring, or a combination thereof, which may be substituted with a benzene ring.
Although the preferable specific example of L is given to the following, it is not limited to these. In the specific examples, it is bonded to the triphenylene ring by *.

  n is preferably 1 to 5, and more preferably 1 to 4.

  In another embodiment of the present invention, the triphenylene derivative represented by the general formula (Tp-1) is preferably a triphenylene derivative represented by the following general formula (Tp-4).

(In General Formula (Tp-4), Ar ² in the case where a plurality of Ar ² are the same, Ar ² represents a cyano group, an alkyl group, a phenyl group, a naphthyl group, a triphenylenyl group, or a group formed by combining these. p and q each independently represents 0 or 1, but p and q are not simultaneously 0. When p and q represent 0, Ar ² represents a hydrogen atom.)

Ar ² is preferably a group formed by combining an alkyl group having 1 to 4 carbon atoms, a phenyl group, a naphthyl group, or a triphenylenyl group, and more preferably a combination of a methyl group, a t-butyl group, a phenyl group, or a triphenylenyl group. It is a group consisting of
Ar ² is particularly preferably a benzene ring substituted at the meta position with an alkyl group having 1 to 4 carbon atoms, a phenyl group, a naphthyl group, a triphenylenyl group, or a combination thereof.

When the triphenylene derivative according to the present invention is used as a host material of a light emitting layer of an organic electroluminescent device or a charge transport material of a layer adjacent to the light emitting layer, an energy gap in a thin film state (a light emitting material is a phosphorescent light emitting material). In such a case, if the lowest excited triplet (T ₁ ) energy in the thin film state is large, the emission is prevented from quenching, which is advantageous for improving the efficiency. On the other hand, from the viewpoint of chemical stability of the compound, it is preferable that the energy gap and T ₁ energy are not too large. The T ₁ energy in the film state of the triphenylene derivative represented by the general formula (Tp-1) is preferably 52 kcal / mol or more and 80 kcal / mol or less, and 55 kcal / mol or more and 68 kcal / mol or less. More preferably, it is 58 kcal / mol or more and 63 kcal / mol or less. In particular, when a phosphorescent light emitting material is used as the light emitting material, the T ₁ energy is preferably in the above range.

The T ₁ energy can be obtained from the short wavelength end of a phosphorescence emission spectrum of a thin film of material. For example, a material is deposited on a cleaned quartz glass substrate to a film thickness of about 50 nm by a vacuum deposition method, and the phosphorescence emission spectrum of the thin film is F-7000 Hitachi Spectrofluorimeter (Hitachi High-Technologies) under liquid nitrogen temperature. Use to measure. The T ₁ energy can be obtained by converting the rising wavelength on the short wavelength side of the obtained emission spectrum into energy units.

  Specific examples of the triphenylene derivative according to the present invention are illustrated below, but the present invention is not limited thereto.

The compounds exemplified as the aromatic hydrocarbon compounds according to the present invention can be synthesized by the methods described in WO05 / 013388 pamphlet, WO06 / 130598 pamphlet, and WO09 / 021107 pamphlet.
After synthesis, it is preferable to purify by sublimation purification after purification by column chromatography, recrystallization or the like. By sublimation purification, not only can organic impurities be separated, but inorganic salts and residual solvents can be effectively removed.

In addition to the light emitting layer, the triphenylene derivative is more preferably contained in an organic layer adjacent to the light emitting layer between the light emitting layer and the cathode, but its use is not limited, and It may be further contained in any layer. The introduction layer of the triphenylene derivative according to the present invention is contained in one or more of the light emitting layer, the hole injection layer, the hole transport layer, the electron transport layer, the electron injection layer, the exciton block layer, and the charge block layer. be able to.
The organic layer adjacent to the light emitting layer between the light emitting layer and the cathode and containing the triphenylene derivative is preferably a charge blocking layer or an electron transporting layer, and more preferably a charge blocking layer.
By including the triphenylene derivative in a layer adjacent to the light emitting layer, the efficiency and durability of the device are improved. When the light-emitting layer is excited, excitons are biased toward the interface between the light-emitting layer and the adjacent layer, causing a phenomenon that destroys the adjacent layer, but the triphenylene derivative has a highly durable structure and is therefore destroyed by the exciton. Since it is difficult, it is thought that the above effects can be obtained.

The triphenylene derivative is preferably composed of only carbon atoms and hydrogen atoms from the viewpoint of ease of synthesis.
When the triphenylene derivative is contained in a layer other than the light emitting layer, it is preferably contained in an amount of 70 to 100% by mass, more preferably 85 to 100% by mass. When the triphenylene derivative is contained in the light emitting layer, it is preferably included in an amount of 0.1 to 99% by weight, more preferably 1 to 95% by weight, and more preferably 10 to 95% by weight based on the total weight of the light emitting layer. More preferably,

  The glass transition temperature (Tg) of the triphenylene derivative according to the present invention is preferably 60 ° C. or higher and 400 ° C. or lower from the viewpoint of stably operating the organic electroluminescent device against heat generated during high temperature driving or driving the device. The temperature is more preferably 65 ° C. or more and 300 ° C. or less, and further preferably 80 ° C. or more and 180 ° C. or less.

  The host material is preferably a highly planar host material (hereinafter also referred to as “flat plate host compound”) because the regularity of the arrangement state becomes higher. Specifically, the aspect ratio is A compound having a shape of 3 or more is more preferable.

The aspect ratio is the ratio (molecular length / molecular thickness) between the molecular length and the molecular thickness of the compound.
From the viewpoint of orientation, the host material used in the present invention preferably has an aspect ratio of 3 or more, and more preferably has an aspect ratio of 3.5 or more.
Here, the molecular length and the molecular thickness are synonymous with those defined in the description of the light emitting layer.
Furthermore, the host material used in the light emitting layer of the present invention is preferably a discotic compound among the flat host compounds, and more preferably a discotic liquid crystalline host compound corresponding to the following.

[Discotic liquid crystalline host compound]
The discotic liquid crystalline host compound forms a liquid crystal phase composed of highly planar disk-like molecules.

The discotic liquid crystalline host compound also includes a compound having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation.
The discotic liquid crystalline host compound is preferably selected from any of triphenylene derivatives, pyrene derivatives, triazine derivatives, and carbazole derivatives, and may be selected from any of triphenylene derivatives, pyrene derivatives, and triazine derivatives. More preferred is a triphenylene derivative, most preferred.

[Discotic liquid crystalline triphenylene derivatives]
As the triphenylene derivative exhibiting liquid crystallinity, any conventionally known discotic liquid crystalline triphenylene derivative can be used, and examples thereof include a triphenylene derivative represented by the following general formula (TI).

In the above general formula (T-I), R _T represents R _T ¹ —, R _T ¹ —O—, R _T ¹ —CO—O—, or R _T ¹ —O—CO—. Although all the compounds having these groups are not discotic liquid crystalline, an appropriate group that exhibits discotic liquid crystallinity can be selected and used based on known techniques. As R _T ^1, there are an alkyl group, an aryl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is arranged between carbon and carbon of the alkyl group, and the like.

As R _T , specifically, R _T ² —, R _T ² —O—, R _T ² —O—R _T ³ —, R _T ² —O—R _T ³ —O—, R _T ² — O—Ph—COO—, R _T ² — (O—R _T ³ ) _nT —O—Ph—COO—, R _T ² —O—Ph—CH═CH—COO—, CH ₂ = CH—COO—R _T ³ —O—Ph—COO— may be mentioned. Here, R _T ² represents an alkyl group which may have a polymerizable group, R _T ³ represents an alkylene group, Ph represents a phenylene group which may have a substituent, n _T , Is a repeating number _of- (O-R _T ³ )-and represents an integer of 1 or more.

R _T ² represents an alkyl group which may have a polymerizable group, when having a polymerizable group, it is preferable from the viewpoint of the expression of the N _D phase having a polymerizable group at the top end of the alkyl group. Examples of the polymerizable group include an acrylic acid ester group, a methacrylic acid ester group, a crotonic acid ester group, and an epoxy group. From the viewpoint of polymerization speed, ease of synthesis, and cost, an acrylic acid ester group and a methacrylic acid ester group. Groups are preferred, and acrylate groups are more preferred.
Carbon number of the alkyl group part in the alkyl group which may have a polymerizable group represented by R _T ² is preferably in the range of 1-20, more preferably in the range of 1-15, and further Preferably it is the range of 3-10.
The number of carbon atoms of the alkylene group represented by R _T ³ is preferably in the range of 1 to 20, more preferably in the range of 1 to 15, and still more preferably in the range of 3 to 10.
Ph represents a phenylene group which may have a substituent group, includes as the substituent also be a halogen atom such as fluorine atom, an alkyl group, an alkoxy group, and the expression of the N _D phase From the viewpoint, an alkyl group is preferable. The number of carbon atoms of the alkyl group or alkoxy group as a substituent is preferably in the range of 1 to 20, more preferably in the range of 1 to 10, and still more preferably in the range of 1 to 6.
n _{T ^{is, - (O-R T 3}} ) - number of repetitions of the represents an integer of 1 or more. n _T is preferably an integer of 1 to 10, more preferably an integer from 1 to 6, more preferably an integer of 1 to 3.

The R _T, in terms of expression of the _{N D ^{phase, R T 2 -O-Ph-}} COO-, R T 2 - (O-R T 3) n T -O-Ph-COO-, R T 2 -O-Ph-CH = CH- COO- is ^{_{preferred, R T 2 -O-Ph-}} COO- are more preferred.

Triphenylene derivative represented by the above general formula (T-I) in that they express the N _D phase, it is preferably a triphenylene derivative represented by the following general formula (T-II).

In the general formula (T-II), R _T ′ represents R _T ² —O—Ph—CO—, R _T ² — (O—R _T ³ ) n _T— O—Ph—CO—, or R _T ^{It represents 2-} O-Ph-CH = CH-CO-. The definitions of R _T ² , Ph, R _T ³ , and n _T are synonymous with R _T ² , Ph, R _T ³ , and n _{T in} the general formula (TI). Specific examples and preferred ranges of R _T ² , Ph, R _T ³ , and n _{T in} the general formula (T-II) are the same as those in the general formula (T-I).

R _T ', since the expression of _{N D} phase is good, the following general formula (T-II-1) ~ It is more preferably represented by any one of (T-II-5).

In the general formulas (T-II-1) to (T-II-5), n and n ′ each independently represent an integer of 1 or more.
X _T represents a polymerizable group.

n represents an integer of 1 or more. n is preferably an integer of 1 to 20, more preferably an integer of 1 to 15, and still more preferably an integer of 3 to 10.
n ′ represents an integer of 1 or more. n ′ is preferably an integer of 1 to 10, more preferably an integer of 1 to 6, and still more preferably an integer of 1 to 3.
X _T represents a polymerizable group, and specific examples and preferred ranges are specific examples of the general formula (T-I) in which may have an alkyl group represented by R _T ² polymerizable groups and This is the same as the preferred range.

  The triphenylene derivative represented by the above general formula (TI) is also preferably a triphenylene derivative represented by the following general formula (T-III) in that it is resistant to electrical oxidation.

In the general formula (T-III), R _T represents R _T ¹ —, R _T ¹ —O—, R _T ¹ —CO—O—, or R _T ¹ —O—CO—. As R _T ^1, there are an alkyl group, an aryl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is arranged between carbon and carbon of the alkyl group, and the like. Specific examples and preferred ranges of R _T is the same as the specific examples and preferred ranges of R _T in the general formula (T-I).

  Among the triphenylene derivatives exhibiting liquid crystallinity in the present invention, those that cause the liquid crystal phase to be expressed in the range of 20 ° C to 300 ° C are preferable. More preferably, it is 40 degreeC-280 degreeC, More preferably, it is 60 degreeC-250 degreeC. Here, the expression of the liquid crystal phase at 20 ° C. to 300 ° C. also means that the liquid crystal temperature range extends over 20 ° C. (for example, 10 ° C. to 22 ° C.) or 300 ° C. (for example, 298 ° C. to 310 ° C.). Including. The same applies to 40 ° C to 280 ° C and 60 ° C to 250 ° C.

  Specific examples of the triphenylene derivative exhibiting liquid crystallinity are shown below, but the present invention is not limited thereto.

  The content of the host material in the light emitting layer of the present invention is preferably 15 to 97% by mass in the light emitting layer, more preferably 30 to 95% by mass, and still more preferably 50 to 95% by mass. .

(Charge transport layer)
The charge transport layer refers to a layer in which charge transfer occurs when a voltage is applied to the organic electroluminescent element. Specific examples include a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, and an electron injection layer.

-Hole injection layer, hole transport layer-
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side.
In the present invention, the organic layer preferably includes a hole injection layer or a hole transport layer containing an electron-accepting dopant.
Materials used for the hole injection layer and the hole transport layer include arylamine derivatives such as 2-TNATA, TPD, NPD, and DNTPD, carbazole derivatives such as CBP, mCP, and TCTA, copper phthalocyanine, titanyl phthalocyanine, and the like. Phthalocyanine derivative, alpha-4T. Known materials such as thiophene derivatives such as Alpha 6T, fluorene derivatives, quinoxaline derivatives, and the like can be mentioned, and arylamine derivatives, phthalocyanine derivatives, quinoxaline derivatives, and carbazole derivatives are preferable, and arylamine derivatives and quinoxaline derivatives are more preferable.
The thickness of the hole injection layer is generally 5 nm to 200 nm, preferably 10 nm to 100 nm, and more preferably 10 nm to 80 nm.
The thickness of the hole transport layer is generally 5 nm to 200 nm, preferably 5 nm to 100 nm, and more preferably 5 nm to 80 nm.

-Electron injection layer, electron transport layer-
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side.
Examples of materials used for the electron injection layer and the electron transport layer include oxadiazole derivatives such as PBD and tertiary butyl PBD, imidazopyridine derivatives, triphenylene derivatives, azacarbazole derivatives, phenanthrene derivatives such as Bphen and BCP, Alq ₃ , Known materials such as aluminum complexes such as Balq, metal complexes such as gallium complexes, zinc complexes, and the like, preferably metal complexes such as imidazopyridine derivatives, triphenylene derivatives, phenanthrene derivatives, aluminum complexes, gallium complexes, zinc complexes, and more Preferred are imidazopyridine derivatives, triphenylene derivatives, phenanthrene derivatives, and aluminum complexes.
The thickness of the electron injection layer is generally 5 nm to 100 nm, preferably 20 nm to 80 nm, and more preferably 25 nm to 60 nm.
The film thickness of the electron transport layer is generally 1 nm to 100 nm, preferably 20 nm to 80 nm, and more preferably 25 nm to 60 nm.

  Regarding the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer, the matters described in paragraph numbers [0165] to [0167] of JP-A-2008-270736 can be applied to the present invention. .

-Hole blocking layer-
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
Examples of the organic compound constituting the hole blocking layer include aluminum (III) bis (2-methyl-8-quinolinolato) 4-phenylphenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4- aluminum complexes such as phenylphenolate (abbreviated as BAlq), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-) phenanthroline derivatives such as phenanthroline (abbreviated as BCP)) and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure made of one or more of the materials described above, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

-Electronic block layer-
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side. In the present invention, an electron blocking layer can be provided as an organic layer adjacent to the light emitting layer on the anode side.
As an example of the organic compound constituting the electron block layer, for example, those mentioned as the hole transport layer described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The electron blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

(First intermediate organic layer)
The first intermediate organic layer in the present invention is composed of at least one organic layer located between the anode and the light emitting layer, and the at least one organic layer includes the above-described hole injection layer, hole transport layer, An electronic block layer is mentioned. The first intermediate organic layer preferably contains at least one hole transport layer, and more preferably comprises a hole injection layer and a hole transport layer.
The film thickness T1 of the first intermediate organic layer is generally 5 nm to 200 nm, preferably 10 nm to 150 nm, and more preferably 10 nm to 120 nm.

(Second intermediate organic layer)
The second intermediate organic layer in the present invention is composed of at least one organic layer located between the cathode and the light emitting layer. Examples of the at least one organic layer include the above-described hole blocking layer, electron transport layer, electron An injection layer is mentioned. The second intermediate organic layer preferably contains at least one electron transport layer, and more preferably comprises two electron transport layers, or an electron injection layer and an electron transport layer.
The film thickness T2 of the second intermediate organic layer is greater than 20 nm and less than 80 nm, preferably greater than 20 nm and less than 80 nm, and more preferably 25 nm or more and less than 60 nm from the viewpoint of power efficiency.

(Film thickness T1 of the first intermediate organic layer, film thickness T2 of the second intermediate organic layer)
In the present invention, the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.1 <T1 / T2 <4.0, and 20 nm <T2 <80 nm, but from the viewpoint of external quantum efficiency and power efficiency, preferably 1.2 <T1 / T2 <3.5 and 20 nm <T2 <80 nm, more preferably 1.2 <T1 / T2 <3.0 and 25 nm <T2 <80 nm.

When the maximum emission wavelength of the light emitting material according to the present invention is 600 to 700 nm, the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.2 <T1 / T2 <4.0 and 30 nm <T2 <80 nm are preferable from the viewpoint of external quantum efficiency and power efficiency. More preferably, 1.5 <T1 / T2 <3.5 and 30 nm <T2 <80 nm, and still more preferably 1.8 <T1 / T2 <3.0 and 50 nm <T2 <80 nm. is there.
Examples of the light emitting material having a maximum light emission wavelength of 600 to 700 nm include the aforementioned platinum complex.

When the maximum emission wavelength of the light emitting material according to the present invention is 400 to 500 nm, the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.1 <T1 / T2 <3.0 and 20 nm <T2 <70 nm are preferable from the viewpoint of external quantum efficiency and power efficiency. More preferably, 1.2 <T1 / T2 <2.8 and 25 nm <T2 <60 nm, and still more preferably 1.2 <T1 / T2 <2.5 and 30 nm <T2 <50 nm. is there.
Examples of the light-emitting material having a maximum emission wavelength of 400 to 500 nm include the above-described pyrene derivatives and π-conjugated compounds, and a pyrene derivative is preferable.

  The maximum emission wavelength of the luminescent material can be measured by an absolute quantum yield measuring device, a spectrofluorometer, or the like.

<Protective layer>
In the present invention, the entire organic EL element may be protected by a protective layer.
Regarding the protective layer, the matters described in paragraph numbers [0169] to [0170] of JP-A-2008-270736 can be applied to the present invention.

<Sealing container>
The element of this invention may seal the whole element using a sealing container.
Regarding the sealing container, the matters described in paragraph No. [0171] of JP-A-2008-270736 can be applied to the present invention.

(Drive)
The organic electroluminescence device of the present invention emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Can be obtained.
The driving method of the organic electroluminescent device of the present invention is described in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-2441047. The driving methods described in each publication, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429 and 6,023,308 can be applied.

  The light-emitting element of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine uneven pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer, etc. It is possible to improve efficiency and to improve external quantum efficiency and power efficiency.

  The light-emitting element of the present invention is a so-called top emission method in which light emission is extracted from the anode side.

The organic EL element in the present invention may have a resonator structure. For example, a multilayer mirror made of a plurality of laminated films having different refractive indexes, a transparent or translucent electrode, a light emitting layer, and a metal electrode are superimposed on a transparent substrate. The light generated in the light emitting layer resonates repeatedly with the multilayer mirror and the metal electrode as a reflection plate.
In another preferred embodiment, a transparent or translucent electrode and a metal electrode each function as a reflecting plate on a transparent substrate, and light generated in the light emitting layer repeats reflection and resonates between them.
In order to form a resonant structure, the optical path length determined from the effective refractive index of the two reflectors and the refractive index and thickness of each layer between the reflectors is adjusted to an optimum value to obtain the desired resonant wavelength. Is done. The calculation formula in the case of the first embodiment is described in JP-A-9-180883. The calculation formula in the case of the second aspect is described in Japanese Patent Application Laid-Open No. 2004-127795.

The external quantum efficiency of the organic electroluminescent element of the present invention is preferably 5% or more, more preferably 7% or more. The value of the external quantum efficiency should be the maximum value of the external quantum efficiency when the device is driven at 20 ° C., or the value of the external quantum efficiency near 100 to 300 cd / m ² when the device is driven at 20 ° C. Can do.

  The internal quantum efficiency of the organic electroluminescence device of the present invention is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more. The internal quantum efficiency of the device is calculated by dividing the external quantum efficiency by the light extraction efficiency. In a normal organic EL element, the light extraction efficiency is about 20%. However, the substrate shape, electrode shape, organic layer thickness, inorganic layer thickness, organic layer refractive index, inorganic layer refractive index, etc. By devising it, it is possible to increase the light extraction efficiency to 20% or more.

(Use of light-emitting element of the present invention)
The light-emitting element of the present invention is a light-emitting device, pixel, display element, display device, display, backlight, electrophotography, illumination light source, illumination device, recording light source, exposure light source, reading light source, sign, signboard, interior, or optical communication It can utilize suitably for etc. In particular, it is preferably used for a device that is driven in a region where light emission luminance is high, such as a light emitting device, a lighting device, and a display device.

Next, the light emitting device of the present invention will be described with reference to FIG.
The light emitting device of the present invention uses the organic electroluminescent element.
FIG. 2 is a cross-sectional view schematically showing an example of the light emitting device of the present invention.
The light emitting device 20 in FIG. 2 includes a transparent substrate (supporting substrate) 2, an organic electroluminescent element 10, a sealing container 16, and the like.

The organic electroluminescent device 10 is configured by sequentially laminating an anode (first electrode) 3, an organic layer 11, and a cathode (second electrode) 9 on a substrate 2. A protective layer 12 is laminated on the cathode 9, and a sealing container 16 is provided on the protective layer 12 with an adhesive layer 14 interposed therebetween. In addition, a part of each electrode 3 and 9, a partition, an insulating layer, etc. are abbreviate | omitted.
Here, as the adhesive layer 14, a photocurable adhesive such as an epoxy resin or a thermosetting adhesive can be used, and for example, a thermosetting adhesive sheet can also be used.

  The use of the light-emitting device of the present invention is not particularly limited, and for example, in addition to a lighting device, a display device such as a television, a personal computer, a mobile phone, and electronic paper can be used.

(Lighting device)
Next, an illumination device according to an embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a cross-sectional view schematically showing an example of a lighting device according to an embodiment of the present invention.
As shown in FIG. 3, the illumination device 40 according to the embodiment of the present invention includes the organic EL element 10 and the light scattering member 30 described above. More specifically, the lighting device 40 is configured such that the substrate 2 of the organic EL element 10 and the light scattering member 30 are in contact with each other.
The light scattering member 30 is not particularly limited as long as it can scatter light. In FIG. 3, the light scattering member 30 is a member in which fine particles 32 are dispersed on a transparent substrate 31. As the transparent substrate 31, for example, a glass substrate can be preferably cited. As the fine particles 32, transparent resin fine particles can be preferably exemplified. As the glass substrate and the transparent resin fine particles, known ones can be used. In such an illuminating device 40, when light emitted from the organic electroluminescent element 10 is incident on the light incident surface 30A of the scattering member 30, the incident light is scattered by the light scattering member 30, and the scattered light is emitted from the light emitting surface 30B. It is emitted as illumination light.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, substance amounts and ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
Hereinafter, the mixing ratio of the solvent represents a volume ratio.

(Synthesis Example 1)
<Synthesis of E-1>

(Synthesis of Compound 1a)
5 drops of acetic acid was added dropwise to an ethanol solution (30 ml) of 2-hydroxy-4-methoxybenzaldehyde (1.6 g) and 4,5-dimethyl-1,2-phenylenediamine (0.73 g) with a 1 ml Komagome pipette. The reaction was carried out at 6 ° C. for 6 hours. The precipitated solid was collected by filtration and recrystallized with ethanol to obtain Compound 1a (2.0 g).
(Synthesis of E-1)
To a solution of compound 1a (0.9 g) and sodium acetate (0.19 g) in acetonitrile (30 ml), a solution of PtCl ₂ (0.61 g) in DMSO (dimethyl sulfoxide) (15 ml) was added dropwise at 80 ° C. for 7 hours. Reacted. The reaction solution was filtered and recrystallized with THF to obtain E-1 (1.04 g). The compound was identified by elemental analysis, NMR and MASS spectrum.

(Evaluation of PL (photoluminescence) retention rate)
<Experimental example 1>
The cleaned quartz substrate is put into a vapor deposition apparatus, and a film (light emitting layer) is prepared by co-depositing the host material and the light emitting material shown in Table 1 below with the doping concentration (mass concentration) of the light emitting material shown in Table 1 below. Was referred to as an element B.
On the film formed in the element B, 70 nm of metal aluminum was deposited in this order to form a cathode.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The element obtained by stopping was designated as element A.
As the order parameter (orientation degree (S)) of the light emitting material in the light emitting layers of the element A and the element B, the film (light emitting layer) formed as described above was calculated by measuring the angle change of ATR-IR. .
Further, by measuring the quantum yield of each element using an absolute PL quantum efficiency measuring device C9220-02 (manufactured by Hamamatsu Photonics Co., Ltd.), the absolute PL (photoluminescence) of the manufactured elements A and B Quantum efficiency was measured and designated PL (A) and PL (B), respectively.
From the obtained PL (A) and PL (B), the PL (photoluminescence) retention rate was calculated as follows.
PL retention ratio = PL (A) / PL (B)
In general, by laminating a metal (such as the above-described metal aluminum), a light wave component that vibrates in a direction perpendicular to the metal out of the phosphorescent component that is photoexcited and generated is extinguished by the metal, so that the film is exposed to the outside. It is not released and the quantum yield / PL retention decreases. On the other hand, when the light emitting material is oriented, quenching is reduced and PL retention is increased (ie, maintained).

<Experimental Examples 2 and 3>
The order parameter (degree of orientation (S)) was the same as in Experimental Example 1 except that the host material, the light emitting material, and the doping concentration (mass concentration) of the light emitting material in Experimental Example 1 were changed as described in Table 1 below. And PL retention was determined. The above results are shown in Table 1 below.

  The structures of the light emitting material and the host material described in Table 1 are shown below.

  As can be seen from the results in Table 1, the higher the order parameter (orientation degree (S)) of the light emitting material in the light emitting layer, the higher the PL retention, and the experimental example 1 in which the order parameter is 0.7 or more is particularly PL. Excellent retention. This is presumably because when the order parameter is 0.7 or more, the ratio of light emission of the component that is quenched by metal is greatly reduced, and the efficiency of light that can be extracted to the outside (glass substrate) is improved. Therefore, a device having an order parameter of 0.7 or more as in the present invention can achieve a higher external quantum efficiency than a conventional device that does not satisfy the condition of the order parameter.

(Examples 1-3 and Comparative Examples 1-7)
A glass substrate (OA-10, manufactured by Nippon Electric Glass Co., Ltd., surface resistance 10Ω / □ (also referred to as Ω / sq.), Refractive index 1.47) having an ITO film having a thickness of 0.5 mm and a 2.5 cm square is washed. After putting into a container and ultrasonically washing in 2-propanol, UV-ozone treatment was performed for 30 minutes. The following organic layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
First layer (hole injection layer): HIL-1: film thickness 10 nm
Second layer (hole transport layer): HTL-1: film thickness 50 nm
Third layer (light emitting layer): E-1 and H-1 (mass ratio 9:91): film thickness 30 nm
Fourth layer (first electron transport layer): Balq: film thickness 5 nm
Fifth layer (second electron transport layer): Alq ₃ : film thickness 30 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode. In addition, although 1 nm of lithium fluoride is a layer located between a light emitting layer and a cathode, since it is an inorganic layer, it is not included in the film thickness of the 2nd intermediate | middle organic layer of this application.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of Example 1 was obtained.
In addition, as an order parameter (orientation degree (S)) of the light emitting material in the light emitting layer of the element of Example 1, the washed quartz substrate was put into a vapor deposition apparatus and the same material and composition as the above third layer (light emitting layer). A film (light emitting layer) in which a light emitting material and a host material are co-evaporated is prepared, and the order parameter (orientation degree (S)) of the light emitting material in the film calculated by measuring the angle change of ATR-IR. Values were used. In addition, it was confirmed that the order parameter (orientation degree (S)) of the light emitting material calculated in this way was 0.7 or more that the light emitting material was oriented in the horizontal direction with respect to the substrate.
Similarly, each element of Examples 2 and 3 and Comparative Examples 1 to 7 was obtained in the same manner as Example 1 except that the material and film thickness of each layer were changed to those shown in Table 2 below.

The performance of the device was evaluated as follows.
(A) External quantum efficiency Using a source measure unit 2400 manufactured by Toyo Technica, a direct current voltage was applied to each element to emit light, and the luminance was measured using a luminance meter BM-8 manufactured by Topcon Corporation. The emission spectrum and emission wavelength were measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. Based on these, the external quantum efficiency with a luminance of around 500 cd / m ² was calculated by the luminance conversion method.
In addition, about Example 1-3 and Comparative Examples 1-3, the relative value when the result of the external quantum efficiency in the comparative example 1 was set to 1.0 was described in Table 2. The higher the number, the better the efficiency.
For Comparative Examples 4 and 5, the relative value when the result of external quantum efficiency in Comparative Example 5 was 1.0 was used. For Comparative Examples 6 and 7, the result of external quantum efficiency in Comparative Example 7 was 1. Table 2 shows the relative values when.

(B) Power efficiency Using a source measure unit 2400 manufactured by Toyo Technica, a direct current voltage was applied to each element to emit light, and the luminance was measured using a luminance meter BM-8 manufactured by Topcon Corporation. The emission spectrum and emission wavelength were measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. Based on these, the power efficiency (lm / W) when the luminance was around 500 cd / m ² was calculated. In addition, about Examples 1-3 and Comparative Examples 1-3, the relative value when the result of the power efficiency in the comparative example 1 was set to 1.0 was described in Table 2. For Comparative Examples 4 and 5, the relative value when the result of power efficiency in Comparative Example 5 is 1.0 is shown. For Comparative Examples 6 and 7, the result of power efficiency in Comparative Example 7 is 1.0. The relative values are shown in Table 2. The higher the number, the better the efficiency.

  The above results are shown in Table 2 below together with the thickness T1 of the first intermediate organic layer, the thickness T2, T1 / T2 of the second intermediate organic layer, and the maximum emission wavelength of the light emitting material in each element.

  The structures of materials other than those listed above in Table 2 are shown below.

From the results of Table 2, when comparing Examples 1 to 3 and Comparative Examples 1 to 3 having the same order parameter (degree of orientation (S)), 1.1 <T1 / T2 <4.0 and T2 In Examples 1 to 3 that satisfy the relationship of <80 nm, the external quantum efficiency and power efficiency were improved compared to Comparative Examples 1 to 3. Moreover, from Comparative Examples 4 and 5, and Comparative Examples 6 and 7, when the order parameter (degree of orientation (S)) is less than 0.7, Comparative Example satisfying the relationship 1.1 <T1 / T2 <4.0 4 and 6 tended to have the same or inferior external quantum efficiency and power efficiency relative to Comparative Examples 5 and 7 that did not satisfy the relationship.
As described above, the embodiment of the present invention satisfying the relationship of 1.1 <T1 / T2 <4.0 and T2 <80 nm with an order parameter (degree of orientation (S)) of 0.7 or more, It can be seen that both high external quantum efficiency and high power efficiency can be satisfied simultaneously.

Example 4
A glass substrate (OA-10, manufactured by Nippon Electric Glass Co., Ltd., ITO layer thickness: 70 nm, substrate refractive index 1.47) having an ITO film having a thickness of 0.7 mm and a 2.5 cm square is placed in a cleaning container, After ultrasonic cleaning in 2-propanol, UV-ozone treatment was performed for 30 minutes. The following organic layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
First layer (hole injection layer): HIL-2: film thickness 40 nm
Second layer (hole transport layer): HTL-2: film thickness 10 nm
Third layer (light emitting layer): BE-1 and H-3 (mass ratio 5:95): film thickness 30 nm
Fourth layer (first electron transport layer): ETL-3: film thickness 30 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode. In addition, although 1 nm of lithium fluoride is a layer located between a light emitting layer and a cathode, since it is an inorganic layer, it is not included in the film thickness of the 2nd intermediate | middle organic layer of this application.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of Example 4-1 was obtained.
Similarly, each element of Examples 4-2 to 9 and Comparative Examples 8-1 to 5 was performed in the same manner as Example 4-1, except that the material and film thickness of each layer were changed to the materials and film thicknesses shown in Table 3 below. Got.
The external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 8-1 are shown in the table below together with the order parameter (orientation (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emission wavelength of the light emitting material. 3.

(Example 5)
Each element of Examples 5-1 to 9 and Comparative Examples 9-1 to 5 was obtained in the same manner as Example 4-1, except that the material and film thickness of each layer were changed to those shown in Table 4 below. It was.
The external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 9-1 are shown in the table below together with the order parameter (orientation (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emission wavelength of the light emitting material. 4.

(Example 6)
Each element of Examples 6-1 to 9-1 and Comparative Examples 10-1 to 5 was obtained in the same manner as Example 4-1, except that the material and film thickness of each layer were changed to those shown in Table 5 below. It was.
The external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 10-1 are shown in the table below together with the order parameter (orientation (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emission wavelength of the light emitting material. 5.

(Example 7)
Each element of Examples 7-1 to 9 and Comparative Examples 11 to 5 was obtained in the same manner as Example 4-1, except that the material and film thickness of each layer were changed to the materials and film thicknesses shown in Table 6 below. It was.
The external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 11-1 are shown in the following table together with the order parameters (orientation degree (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emission wavelength of the light emitting material. 6.

  The structure of the material described in Tables 3-6 is shown below.

  Even when a fluorescent material is used as the light emitting material from the results of Tables 3 to 6, the order parameter (degree of orientation (S)) is 0.7 or more, 1.1 <T1 / T2 <4.0, and It can be seen that the embodiment of the present invention satisfying the relationship of 20 nm <T2 <80 nm can satisfy both high external quantum efficiency and high power efficiency at the same time.

(Example 8)
A glass substrate (OA-10, manufactured by Nippon Electric Glass Co., Ltd., ITO layer thickness: 70 nm, substrate refractive index 1.47) having an ITO film having a thickness of 0.7 mm and a 2.5 cm square is placed in a cleaning container, After ultrasonic cleaning in 2-propanol, UV-ozone treatment was performed for 30 minutes. The following organic layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
First layer (hole injection layer): HIL-2: film thickness 40 nm
Second layer (hole transport layer): HTL-2: film thickness 10 nm
Third layer (light emitting layer): BE-1 and H-3 (mass ratio 5:95): film thickness 25 nm
Fourth layer (first electron transport layer): ETL-1: film thickness 30 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode. In addition, although 1 nm of lithium fluoride is a layer located between a light emitting layer and a cathode, since it is an inorganic layer, it is not included in the film thickness of the 2nd intermediate | middle organic layer of this application.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of Example 8 was obtained.
(Comparative Example 12)
First layer (hole injection layer): HIL-2: film thickness 95 nm
Second layer (hole transport layer): HTL-2: film thickness 30 nm
The device of Comparative Example 12 was obtained in the same manner as in Example 8 except that the element was changed to.
For the devices of Example 8 and Comparative Example 12, the external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the result of Comparative Example 12 are shown in Table 7 below together with the order parameter (orientation degree (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emission wavelength of the light emitting material. Describe.

Example 9
A glass substrate (OA-10, manufactured by Nippon Electric Glass Co., Ltd., ITO layer thickness: 70 nm, substrate refractive index 1.47) having an ITO film having a thickness of 0.7 mm and a 2.5 cm square is placed in a cleaning container, After ultrasonic cleaning in 2-propanol, UV-ozone treatment was performed for 30 minutes. The following organic layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
First layer (hole injection layer): HIL-2: film thickness 40 nm
Second layer (hole transport layer): HTL-2: film thickness 10 nm
Third layer (light emitting layer): BE-1 and H-3 (mass ratio 5:95): film thickness 40 nm
Fourth layer (first electron transport layer): ETL-1: film thickness 30 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode. In addition, although 1 nm of lithium fluoride is a layer located between a light emitting layer and a cathode, since it is an inorganic layer, it is not included in the film thickness of the 2nd intermediate | middle organic layer of this application.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of Example 9 was obtained.
(Comparative Example 13)
First layer (hole injection layer): HIL-2: film thickness 95 nm
Second layer (hole transport layer): HTL-2: film thickness 30 nm
A device of Comparative Example 13 was obtained in the same manner as in Example 9 except that the element was changed to.
For the elements of Example 9 and Comparative Example 13, the external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 13 are shown in Table 8 below together with the order parameter (orientation (S)) of the light emitting material, the values of T1, T2, T1 / T2 in each element, and the maximum light emitting wavelength of the light emitting material. Describe.

(Example 10-1)
A glass substrate (OA-10, manufactured by Nippon Electric Glass Co., Ltd., ITO layer thickness: 50 nm, substrate refractive index 1.47) having a thickness of 0.7 mm and a 2.5 cm square ITO film is placed in a cleaning container, After ultrasonic cleaning in 2-propanol, UV-ozone treatment was performed for 30 minutes. The following organic layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
First layer (hole injection layer): HIL-2: film thickness 40 nm
Second layer (hole transport layer): HTL-2: film thickness 10 nm
Third layer (light emitting layer): BE-3 and H-3 (mass ratio 5:95): film thickness 30 nm
Fourth layer (first electron transport layer): ETL-1: film thickness 30 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode. In addition, although 1 nm of lithium fluoride is a layer located between a light emitting layer and a cathode, since it is an inorganic layer, it is not included in the film thickness of the 2nd intermediate | middle organic layer of this application.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of Example 10-1 was obtained.

(Example 10-2)
First layer (hole injection layer): HIL-2: film thickness 50 nm
Second layer (hole transport layer): HTL-2: film thickness 15 nm
Example 10-2 was obtained in the same manner as in Example 10-1, except that the device was changed to.

(Comparative Example 14)
First layer (hole injection layer): HIL-2: film thickness 95 nm
Second layer (hole transport layer): HTL-2: film thickness 30 nm
The element of Comparative Example 14 was obtained in the same manner as in Example 10-1, except that the change was made.
For the devices of Examples 10-1 and 10-2 and Comparative Example 14, the external quantum efficiency and power efficiency were calculated in the same manner as in Example 1. The relative values based on the results of Comparative Example 14 are shown in Table 9 below.

  As can be seen from the results of Tables 7 to 9, even when the film thickness of the light emitting layer or ITO film was changed, the order parameter (degree of orientation (S)) was 0.7 or more, and 1.1 <T1 It can be seen that the embodiment of the present invention satisfying the relationship of /T2<4.0 and 20 nm <T2 <80 nm can satisfy both high external quantum efficiency and high power efficiency at the same time.

(Example 11) A mode in which a light scattering layer (light extraction layer) is formed on a substrate [Preparation of fine particle layer transfer material]
<Formation of uneven relief layer>
On a substrate made of a polyethylene terephthalate (PET) film having a thickness of 100 μm, an unevenness reducing layer having an average thickness of 20 μm was formed by applying a coating liquid for unevenness reducing layer having the following composition and drying.
In addition, the average thickness of an uneven | corrugated relaxation layer cuts off a part of uneven | corrugated relaxation layer, and is an average value measured 10 places with the scanning electron microscope (S-3400N, Hitachi High-Tech Co., Ltd.) (hereinafter measured similarly). ).

<< Coating liquid for uneven relief layer >>
Binder A: 40 parts by mass, Binder B: 25 parts by mass, Plasticizer 1:10 parts by mass, Surfactant 1: 0.5 parts by mass, and Methyl ethyl ketone 25 parts by mass are mixed to prepare a coating solution for uneven relief layer. Prepared.
-Binder A-
Methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer (molar ratio) = 55 / 11.7 / 4.5 / 28.8 (trade name: Aromatex FM601, manufactured by Mitsui Chemicals, Ltd., weight (Average molecular weight = 90,000, solid concentration 21% by mass)
-Binder B-
Styrene / acrylic acid copolymer (molar ratio) = 63/37 (trade name: Alloset 7055, manufactured by Nippon Shokubai Co., Ltd., weight average molecular weight = 8,000, solid content concentration 41 mass%)
-Plasticizer 1-
2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane (made by Shin-Nakamura Chemical Co., Ltd.)
-Surfactant 1-
・ The following structure 1 ... 30% by mass

・ Methyl ethyl ketone: 70% by mass
<Formation of intermediate layer>
Next, an intermediate layer having an average thickness of 1.6 μm was formed by applying a coating solution for intermediate layer having the following composition on the unevenness reducing layer and drying it.
-Coating solution for intermediate layer-
Polyvinyl alcohol (PVA205 (saponification rate = 88%), manufactured by Kuraray Co., Ltd.) 2.1 parts by mass, polyvinylpyrrolidone (PVP, K-30; manufactured by ASP Japan Co., Ltd.) 0.95 parts by mass, methanol 44 parts by mass And 53 parts by mass of distilled water were mixed to prepare an intermediate layer coating solution.
<Formation of fine particle layer>
Next, the fine particle layer composition 1 prepared as described below was applied onto the intermediate layer and dried to form a fine particle layer having an average thickness of 10 μm.
<< Fine Particle Layer Composition 1 >>
Fine particle dispersion 1:30 parts by mass and propylene glycol monomethyl ether acetate (MMPG-Ac, manufactured by Daicel Chemical Industries) 8 parts by mass were mixed at a temperature of 24 ° C. (± 2 ° C.) and stirred at 150 rpm for 10 minutes. Next, 53 parts by mass of methyl ethyl ketone, 5 parts by mass of binder C, 0.002 parts by mass of hydroquinone monomethyl ether, 4.2 parts by mass of DPHA solution, 2,4-bis (trichloromethyl) -6- [4- (N, N -Diethoxycarbonylmethyl) amino-3-bromophenyl] -s-triazine 0.16 parts by mass, surfactant 1: 0.044 parts by mass at a temperature of 25 ° C. (± 2 ° C.) in this order, The fine particle layer composition was prepared by stirring at a temperature of 40 ° C. (± 2 ° C.) at 150 rpm for 30 minutes.
-Fine particle dispersion 1-
-As 1st microparticles, Nissan Chemical Co., Ltd. Optobead 2000M [solid content 100 mass%] (average particle diameter of 2 micrometers) ... 45 mass%
-As the second fine particles, fine particle titanium oxide MT-05 (average particle size 10 nm, refractive index 2.72) manufactured by Teika Co., Ltd. 9.5% by mass
-Dispersant (compound 1) represented by the following structural formula: 0.5% by mass

-Polymer (benzyl methacrylate / methacrylic acid = 72/28 (molar ratio) random copolymer, weight average molecular weight 37,000) ... 5 mass%
・ Propylene glycol monomethyl ether acetate: 40% by mass

-Binder C-
・ Polymer (benzyl methacrylate / methacrylic acid = 78/22 molar ratio random copolymer, weight average molecular weight 38,000) 27 mass%
・ Propylene glycol monomethyl ether acetate: 73% by mass
-DPHA solution-
Dipentaerythritol hexaacrylate (containing 500 ppm of polymerization inhibitor MEHQ, manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) ... 76% by mass
・ Propylene glycol monomethyl ether acetate: 24% by mass
Finally, a 12 μm-thick polypropylene cover film was stuck on the prepared fine particle layer to provide a fine particle layer transfer material.

A glass substrate (OA-10, Nippon Electric Glass Co., Ltd., refractive index 1.47) is placed in a cleaning container, subjected to ultrasonic cleaning in a neutral detergent, then ultrasonically cleaned in pure water, and 120 ° C. for 120 minutes. Heat drying was performed. After drying, a silane coupling solution [N-β (aminoethyl) γ-aminopropyltrimethoxysilane 0.3 mass% aqueous solution, product name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.] is showered on the substrate for 20 seconds. Spraying, pure water shower cleaning, and heat drying (2 hours at 80 ° C.) were performed.
Next, the cover film is removed from the fine particle layer transfer material produced as described above on the obtained silane coupling treated glass substrate, and the surface of the fine particle layer exposed after the removal and the surface of the silane coupling treated glass substrate Was laminated using a laminator, and laminated on a substrate heated at 100 ° C. for 2 minutes under the conditions of a rubber roller temperature of 130 ° C., a linear pressure of 100 N / cm, and a conveyance speed of 2.2 m / min.
After that, it is exposed with a proximity type exposure machine (manufactured by Nihon Hi-Tech Electronics Engineering Co., Ltd.) having an ultra-high pressure mercury lamp, heat-treated at 100 ° C. for 30 minutes, and the substrate and the fine particle layer are in close contact with each other with almost no gap therebetween. A high refractive index glass substrate with a fine particle layer was prepared as a protective sheet.
Next, ITO (Indium Tin Oxide) was formed to a thickness of 100 nm by sputtering on the surface of the high refractive index glass substrate with the fine particle layer opposite to the fine particle layer.
After the deposition of the first layer (hole injection layer), an organic electroluminescent device was produced in the same manner as in Example 1.

(Example 12) A mode in which a light scattering layer (light extraction layer) is formed on a high refractive index glass substrate having a refractive index of 1.8 or more The SLH-53 (manufactured by OHARA) is used as the glass substrate described in Example 11 above. The organic electroluminescent element was produced in the same manner as in Example 11 except that the refractive index was changed to 1.81).

  About the element produced in the said Examples 11 and 12, external quantum efficiency and power efficiency were evaluated similarly to Example 1. FIG. The results are shown in Table 10 together with the results of Example 1 and Comparative Example 1 listed in Table 2.

  As can be seen from the results in Table 10, external quantum efficiency and power efficiency can be increased by providing a light scattering layer (extraction layer), and a high refractive index glass having a refractive index of 1.8 or more is used as the substrate. It was revealed that higher external quantum efficiency and power efficiency can be obtained.

DESCRIPTION OF SYMBOLS 2 ... Substrate 3 ... Anode 4 ... Hole injection layer 5 ... Hole transport layer 6 ... Light emitting layer 7 ... 1st electron transport layer 8 ... 2nd electron Transport layer 9 ... Cathode 10 ... Organic electroluminescent element 11 ... Organic layer 12 ... Protective layer 14 ... Adhesive layer 15 ... Light extraction layer 16 ... Sealing container 20 ... -Light emitting device 30 ... Light scattering member 30A ... Light incident surface 30B ... Light exit surface 31 ... Transparent substrate 32 ... Fine particles 40 ... Illumination device

Claims (10)

A substrate has an anode, a first intermediate organic layer composed of at least one organic layer, a light emitting layer, a second intermediate organic layer composed of at least one organic layer, and a cathode in this order. An organic electroluminescent device to be taken out,
The light emitting layer contains a light emitting material oriented in the horizontal direction with respect to the substrate, and the order parameter of the light emitting material in the light emitting layer is 0.7 or more,
The relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1.1 <T1 / T2 <4.0 and 20 nm. <T2 <80 nm, an organic electroluminescent element. The organic electroluminescent element according to claim 1, wherein the light emitting material is a platinum complex, a pyrene derivative, or a π-conjugated compound represented by the following general formula (R-1).

(Here, Ar _{1 to} Ar ₃ each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and Ar _{4 to} Ar ₇ each independently represents an aromatic carbon atom having 6 to 30 carbon atoms. Represents a hydrogen group, and two aromatic hydrocarbon groups constituting Ar ₄ and Ar ₅ are bonded directly or via a substituent to form a condensed heterocyclic ring with N substituted by Ar ₄ and Ar _5. Alternatively, two aromatic hydrocarbon groups constituting Ar ₆ and Ar ₇ may be bonded directly or through a substituent to form a condensed heterocyclic ring with N substituted by Ar ₆ and Ar _7. L ₁ and L ₂ each independently represents a vinylene group or an acetylene group, and l, m, n, o and p each independently represent an integer of 0 to 6, but any one of l, n and p One is not 0.)   The organic electroluminescent element according to claim 1, wherein the light emitting layer further contains a host material, and the host material is a triphenylene derivative.   The maximum light emission wavelength of the light emitting material is 600 to 700 nm, and the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1 The organic electroluminescent element according to any one of claims 1 to 3, wherein 0.2 <T1 / T2 <4.0 and 30 nm <T2 <80 nm.   The maximum emission wavelength of the light emitting material is 400 to 500 nm, and the relationship between the film thickness T1 (nm) of the first intermediate organic layer and the film thickness T2 (nm) of the second intermediate organic layer is 1 The organic electroluminescent element according to claim 1, wherein 1 <T1 / T2 <3.0 and 20 nm <T2 <70 nm.   The organic electroluminescent element according to claim 1, wherein a light extraction layer is formed on the substrate.   The organic electroluminescent element according to claim 6, wherein the refractive index of the substrate is 1.8 or more.   The light-emitting device using the organic electroluminescent element of any one of Claims 1-7.   The display apparatus using the organic electroluminescent element of any one of Claims 1-7.   The illuminating device using the organic electroluminescent element of any one of Claims 1-7.

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